Wednesday, 28 April 2010

AGUSTÍ FERNÁNDEZ – Un Llamp Que No S’Acaba Mai


Instantly manufactured during a December 2007 concert in Sigüenza, Spain, this album (whose title translates as “a lightning that never ends”) sounds quite distant from a conjectural sonic translation of that phenomenon. The recording introduces us to a volatile temperament that tends to shed some light over the unknown corners of certain registers, or inquire about assorted aspects of dynamic correlation, ultimately rendering the experience akin to walking across a country area before a storm: the moment in which the sky begins to look threateningly grey, the first crackles are heard and whirlwinds of fallen leaves and pieces of broken branches cause that typical whoosh-and-rustle manifestation that pushes ordinary people to hurry the pace to get home early. On the contrary, it’s right there that this particular set becomes more fascinating. And, in due course, the tempest does arrive (though not unending).

Fernández is not scared of exploiting the uncomfortable traits of the piano. He gives a free rein to bewildering outbreaks that, under an apparently uncongenial structure, hide instead a clarity of vision that’s immediately measurable by proficient ears, which in turn complete elaborate geometries often merely hinted, but fully visualized in advance by their engenderer. The reciprocal behaviour amidst the companions is impeccable, a veritable seminar on how a trio recital should be carried on when the intention is that of making serious music - and a sizeable bit of invigorating noise, too. A fabulous Mark Sanders maintains total control on now bubbling, now mottled percussive textures in an olla podrida of neatly deployed fickle figurations, deliverable only by truly sensitive drummers. John Edwards figures as a catalyzing presence, joining the conversational flow with impious rewordings of the commonly known literature associated to the double bass yet, at the same time, using extended notes and droning clusters to dictate the coordinates of the calmer places where the protagonists occasionally land, intelligently releasing the listener from the grip of unwarranted pressure.

Sunday, 18 April 2010


The Helen Scarsdale Agency

Over several years violist Julia Eckhardt - an artistic director at Brussels’ Q-O2 Werkplaats sound laboratory - has been amassing an extensive number of long-form pieces for solo viola, all of them rigorously in G. These are part of an archive which is available to artists willing to exploit the droning character of that music in heterogeneous settings, differently established each time. After a meeting during a residency, French artist Manu Holterbach decided to use Eckhardt’s drones as the basic constituent for his work, mostly originating from field (and “tubular”…) recordings that include, in this particular occasion, trees, wires, crickets, wind and different kinds of electric manifestation besides instruments like gong, eBowed banjo, other musicians’ rehearsals and Tonton Macoute’s “drone experience for cheap organ”.

The press release mentions Phill Niblock and Andrew Chalk as influences to consider when thinking about who should be the ultimate recipient of this beautiful CD. There’s an inherent static component, of course, but also a factor that partially distances Do-Undo from those names: consonance. This work’s vastness derives in fact from the almost perfect correspondence of the natural sources with the instrumental nuances around the fundamental pitch, devoid of post-processing or transposing. The mixture resonates very naturally: a life-enhancing current, a rehabilitation against the excess of nervous tension. The events succeed without a solution of their continuity, the ears neither capable of deciding what to highlight, nor anxious to focus on a determinate direction of the layered pulses. This goes on for the whole extent of the album, with nary a moment of weariness – which, in this genre, is quite an achievement.

In actuality, the defenselessness characterizing the pseudo-stationary structures of “Julia’s Ecstatic Spring Phenomenon” – which nonetheless remain stable throughout – and the sensitiveness shown in the overall sonic flow’s groundwork had me recalling, at one point, Richard Skelton’s pastorally plangent ebbs and flows. Except that there is no ebb and flow here. The association with maverick minimalists such as the aforementioned Niblock and La Monte Young comes easier in the record’s second half, “Two Stasis Made Of Electricity” (a Young title is even quoted in a sub-chapter). Still, Holterbach and Eckhardt’s gatherings show enough personality for carving a niche of uniqueness in your spirit as they actually did in this writer’s, ever since the first of a series of listens that’s meant to go on.

Thursday, 15 April 2010



Despite his role as a mastermind behind the Gameboy label, the considerable quantity of releases and the abundance of collaborations entertained (including artists respected from yours truly, such as Brendan Murray and Francisco Meirino aka Phroq), this is the first time, if the memory is not failing, that I hear sounds produced by Mike Shiflet. Bad for me, especially in view of the brilliance of this collaboration with Daniel Menche, my impartiality towards the latter well known (sorry, gimme a second as I go lighting up another candle under the Portlander’s icon, heh heh). The sources used were Hammond organs and electronics; the material was recorded between 2007 and 2008. OK, all ready for an amassment of crabby drones? Hold your horses.

The opening movement is constructed upon acute frequencies (initially similar to radio waves, then fusing in a single painful flux), irregular crackling/purring and a low rumble underneath – picture the sound of heavy wind hitting a microphone’s capsule. Factors that appear independent yet mesh with no trouble, providing a tense expectancy tinted with insubstantial colours. No ornamentations, no conjectures, as directly affecting as you can get. The increasing hostility of the subsequent chapter is characterized by the anticipated massive droning – of the flanging / metallic / industrial kind, very threatening indeed – and by an implicit pulse giving an idea of unavoidable virulence. The organ timbre - here as everywhere else - is often hard to distinguish, but one couldn’t really care less: this is sunless music, utterly absorbing and entrancing. Myriads of micro-rhythms and illusory patterns are detected, a magnificent underworld of inappropriate presences gradually turning into the verses of a post-metropolitan poem. The final third comprises bottomless booming, mangled fragments of – again – radio-like emissions, a sense of boiling grimy liquids, additional crackle-and-pop activity. We envision mechanical seagulls fighting for food at one point, then Father Drone comes back with a vengeance and it’s guerilla warfare: vicious ferociousness until the record’s conclusion, signaled by a humongous throb generated in the keyboard’s low-register area.

An outstanding work, heterogeneous and smartly crafted, mixing violence and brainpower in equal doses. Mental purification dressed in timbral infectivity.

MARSFIELD – The Towering Sky

Faraway Press

This record - a project involving Andrew Chalk, Vikki Jackman, Brendan Walls and Robin Barnes – features music recorded in 2005, slightly different from what a superficial listener could expect from this label which traditionally releases works trademarked by temperate nebulosity. Still, if one’s ears are open as required, lots of familiar factors that establish the belonging of The Towering Sky in the same area of sonic investigation are unearthed.

The album is divided in two tracks, a total of circa 37 minutes. The first – “Marsfield Cathedral” – is a wonderful improvisation whose reverberant qualities possess an innate influence that furnishes a suitable environment with a soul of its own. The predominant timbres seem to derive from bowed metals – glass, too? - and resonating bowls, yet I wouldn’t be surprised if processed strings (guitar and piano’s lowest regions, perhaps) had been put in the recipe somewhere. The immediate reaction deceivingly sets us in “expected comparison” mode: one immediately thinks Organum and Mirror, since the room’s corners help those incredibly booming frequencies to morph, ricochet and affirm as it happens with those marvelous entities. There’s a section in which you may be tempted to bet some money on the existence of voices: ghostly undulations, almost disquieting if you will, that make their presence heard for a while and then just disappear. It might be a trick of the mind, though. Better remaining with an attractive doubt, sometimes.

As dramatic as the previous episode is, the group's unique personality is established by “Marsfield Common”, which is centered around a tentative exploration of a large ambience through the use of regular instruments; we guess a harmonium or an accordion (both?) are in there, and maybe a plucked cello, or a viola. What gives the piece strength is not the affirmation of those sparse pitches and stabs amidst a blur of indeterminate details, but that very intangible background going on continuously. Possibly they are tapes reproducing remixed snippets of priorly emitted sounds, or treated field recordings. Whatever it is, this creates a bed for the stream to flow, so to speak. And flow the river does with occasional surges, repeated bumps and, in general, a certain degree of irregularity that, curiously, push the sound towards lands that are usually inhabited by Chalk’s former partner in Ora, Darren Tate. Fairly inexplicable and engrossing, including the splendid conclusion: decreasing intensity and progressive instrumental rarefaction, accompanied by thunder and rain. And, once again, we feel deeply grateful at the end of the experience, not the least for the stunning poetry of the cover artwork: the photo of an ancient bucolic setting with children and sheep that literally defies description.

Monday, 12 April 2010

THE NAKED FUTURE – Gigantomachia

Debut release - issued over a year ago, but WTF - for a hard-hitting quartet formed by Arrington de Dionyso (bass and contralto clarinet), Thollem McDonas (piano), John Niekrasz (drums) and Gregg Skloff (amplified upright bass). “All pieces recorded as improvised according to the conceptual direction of Arrington de Dionyso”, the cover says. The latter’s feverishly vibrant utterances gasp and sizzle in a kind of anti-technical way, as if he preferred his own guts to speak in lieu of the instrument. A courageous choice, given the man’s evident facility. But there’s actually no person in charge here: this is a collective (with a capital C) effort mostly feeding on outrageous conflagrations, memorable torments destined to rape the silken ears of those who usually look for easy ways out when caught up with overly imaginative (for their mind) recordings.

One of the first thoughts during the initial spin was “McDonas at his most Cecil Taylor-esque”, therefore I was happy to read about the same reference at the very beginning of David Keenan’s liners. It’s called “solidarity among writers”. The pianist provides mercurial harmonic shifts, autistic ostinatos and characteristically uncomfortable digital activity as per the norm: still, he occasionally stops (the others do so, too…) and contemplates the past or – ironically - quotes popular styles despite the fact that there is havoc around. The sound of Skloff’s valve-augmented groans puts its box’s timbre in an alley situated halfway through William Parker Drive and Jack Bruce Street, the unquestioning enthusiasm and raging cantankerousness of Niekrasz furnishing the music with a supplementary dose of fickleness that, on the other hand, makes the sonic mass appear even more unyielding. When the boys decide to go pedal-to-the-metal, they reveal themselves to be punker than me (…than Sid Vicious for sure). Great record: play loud, put up the shutters, get wall-knocked by the neighbours, crash your car against a barrier if you are stupid enough to listen to this while driving. Keep living.

Sunday, 11 April 2010

TERESA RAMPAZZI – Musica Endoscopica (Vinyl Edition)

Die Schachtel

This is the first release ever to diffuse the work of Teresa Rampazzi (1914-2001), a pioneer of electronic and computer music who was among the founders of the Centro Di Sonologia Computazionale in Padua, an important association of experimental composers active in Italy. The vinyl copy in my possession differs from the digital version. The alternative track is also the most recent material on offer: 1981’s “Metamorfosi” is an intriguingly ringing sonic cloud, born from the wish of “expressing the continuous mutability of all parameters”. What's missing instead from the CD is "Atmen Noch". Most sincerely, this kind of collector-enticing tactic is absurd, also because the quality of the vinyl is not exceptional - pops and bumps a go go.

In truth, the notes and the excerpts from Rampazzi’s writings and interviews constitute the really interesting ingredient of this edition. We become aware of the composer’s artistic path: primarily an avant-garde pianist and choir member, she remained totally fascinated by a small frequency generator shown to her by Herbert Eimert during a course at Darmstadt. From there, this firm-minded lady went on to analyze and exploit the possibilities of similar instruments, early synthesizers and primordial computers that certainly weren’t designed for interfacing with musicians. A passionate quest for new methods of audio-making, whose fruits and testimonies were donated to the Department Of Visual Arts And Music at Padua’s University two years prior of her death.

Do not be too hopeful for unfathomable sonorities, despite the unconventionality of this woman’s spirit. The record should be played loud, in order to better enjoy at least the essential consistency of unstructured masses of frequencies and noises that don’t sound like compositions, more a series of casual occurrences without a significant impact. Some of these flashes are pretty beautiful and vaguely fascinating, others are merely subsidiary presences, lacking any kind of mystery and interest. The whole first half is dedicated to “Musica Endoscopica”, originally a soundtrack for a documentary on – that’s right – endoscopy. The other side comprises the spacey “Environ” and the fairly unformulated “With The Light Pen” – rather forgettable episodes, if you ask me. The above mentioned “Metamorfosi” is not enough to transform what’s just a somewhat weird document into a must-have. Deep respect goes to Mrs. Rampazzi’s vision and stubborn inquisitiveness, but for sure we’re not talking about a female embodiment of Roland Kayn.

Friday, 9 April 2010



I gave my attentive ears to Cave Rock today for the first time. The record was originally released in 1969 and has been repeatedly reissued, also under the name of Orgasm. It is even featured in the world-famous Nurse With Wound list (apparently, everything contained therein represents some sort of must for easily influenced collectors). The “music”, performed by Austin Grasmere, Brian Elliot and the so-called Connecticut Tribe, is not totally horrific per se: absolute mayhem and disregard for any rule and scheme, warped tapes, bagpipes, radio, bizarre electronics, two-chord steel-stringed strumming, heavily distorted electric guitars, huge percussive slabs. However, nothing so exceptionally ahead of the future as the hype would have it.

The real troubles arise when Cromagnon open their mouths, which is more or less always: it’s there that the whole thing melts down in a huge splodge of incoherent mental diarrhoea. What many critics love to categorize as “freaking out” is in point of fact utter stupidity: awfully exasperating gargling and yelping, drunken/drugged choirs, strained laughter and - the lowest point – a piece called “Ritual Fest Of The Libido”: namely, the sonic equivalent of a retard screaming in agony while strapped to a mattress on fire. Initially this is quite unsettling, but already at the second listen it has become merely pathetic, exactly as the large part of the “vocal work”. There’s a not-so-subtle difference between freedom and uselessness, and the majority of this stuff goes well beyond the limit of art to land in the area where “dada” borders with “doomed to failure”. I picked these extracts from a 2009 write-up (originally published on Dusted):

…Most of the bands that Cromagnon recalls – Faust, Throbbing Gristle, Nurse with Wound, etc. – didn’t exist in 1969. (…) The critical reaction always seems to be the same: how could anything this weird, this prefigurative of industrial out-rock and experimental psyche have possibly been produced in 1969?

An answer might be “probably because Cromagnon (and Faust, and…) had listened to Frank Zappa’s Freak Out, Absolutely Free and We’re Only In It For The Money” (1966 and 1967). The problem is that they lacked Zappa’s intelligence, acute sense of satire and – of course – technical grounds. The history of “alternative” music didn’t start with Throbbing Gristle or NWW, you see. Give me “Return Of The Son Of Monster Magnet”, “Help I’m A Rock” or “The Chrome-Plated Megaphone Of Destiny” over this article for psychologically mired individuals any time. “Industrial out-rock”? “Dadaist psychedelic folk”? To quote Zappa again, this disc is just “a puddle of piddle that used to be little” but has somehow grown to be a cult item. Hours and funds utterly wasted, then like now.

(P.S. There is a new ESP roundup review on Temporary Fault, comprising much better releases than this one).

Thursday, 8 April 2010

ZIMOUN / HELENA GOUGH – Zimoun Featuring Helena Gough


This 20-minute piece is part of a fresh series by Leerraum, juxtaposing stimulating sounds and equally remarkable visual metaphors; all materials are to be found at the label’s website. In this particular case, the audio track accompanies Evelina Domnitch and Dmitry Gelfand's exploration of complex interactions deriving from “upwardly sonicated silicone oil”, a process (described in detail in the liners) that I really didn’t manage to truly understand, but totally fascinating to say the least.

The electroacoustic materials will most evidently appeal to the many listeners who have welcomed the work of Asher Thal-Nir over recent years. In fact these symptoms (concocted by Gough and elaborated by Zimoun) openly call to mind the conversion of urban landscapes altered by a patina of digital griminess typical of the Bostonian. The DVD that Zimoun was so kind to send for review has been endlessly spinning for hours on repeat mode. This is undeniably the best way to get encircled by the mass of incidences, sonic substances active at the unintentional level even as they stuff the ears with clogging rumble, hardly audible yet effectual acute frequencies and layers of hiss and digital rubble that, amazingly, are perceived like a beneficial palliative by an overstressed brain (such as mine these days). However, when we decided to stop the playback the lingering sensation was one of tinnitus, obviously depending on the volume implemented.

There’s not much more as far as descriptive comparisons are concerned, since the whole affair is erected upon these grounds. What’s definitely to recommend is listening to it in diverse ways. Headphones are going to help in unearthing internal micro-rhythms and changes in the equalization that the massive murmur heard in the room via the speakers keeps fairly undisclosed. This lets us appreciate the compositional endeavor, while the “environmental” diffusion is still an excellent means for separating ourselves from the rest of the world and concentrate on the small things that define our physical subsistence.

Monday, 5 April 2010

PETER GARLAND – String Quartets

Cold Blue

Discursiveness is not an option in Peter Garland’s music for string quartet. In the 51 minutes of this graceful record, finely played by Apartment House (Gordon MacKay and Hilary Sturt on violin, Bridget Carey on viola and founder Anton Lukoszevieze on cello), you won’t find an unnecessary note or phrase. All events appear as predisposed to symbolize a state of near-perfection, the kind of harmonious mental condition people rabbits on ceaselessly, hypothetically conquerable with years upon years of “meditative activity” but, in truth, only achieved through other kinds of harmonic processes – the ones instigated by a different, deeper practice of fine tuning.

Indeed, the first sensation experienced as soon as “In Praise Of Poor Scholars” begins is one of accomplishment, of inner quietude. The last verses of T’ao Ch’ien’s poem from which the piece’s title originates recite:

Know your strengths, keep to trodden ways. Who hasn’t known cold and hunger? Those who know me: if they are no longer here - that’s it then. Why complain?

The musicians perform Garland’s tantalizing score with agile susceptibility and ecstatic sentiment, transforming the act of listening in a peaceable commemoration, the acknowledgment of an order of things that might seem casual, yet is going to be understood as ideal as we grow older. Counterpoints and intersections are rather logical – even by non-expert standards – though we’re very far away from the obtuse luxury of certain renowned composers who blend Buddhism and budgets before releasing sterile exercises for ready-to-roar, auditorium-subscribing simpletons. The luminosity and the humble purity of these gentle constructions represent the perfect antidotes to that sort of vulgarity, an authentic compensation for ears tired of humdrum cadenzas and opulent chords that turn an unearned ovation into a mandatory response.

“Crazy Cloud” is a reference to “the pen name of poet-priest Ikkyu (1394-1481)”, and was composed during a residency at the Koninji Temple in Hamochi, on the Japanese island of Sado. This particular Quartet is slightly more affirmative, authoritative in rare occasions, with barely hinted allusions to quasi-Reichian minimalist structures alternated to moments of collected reflection and reserved spirituality (factors influencing the whole album, in case someone is still uncertain). The performance is again flawless, technical exactness manifest but never, ever transcending the limit of a level-headed equanimity bathed in poignant awareness. As always, no useful words exist to convey what the vibration of juxtaposed strings communicates. It’s an undisclosed bliss that will remain forever contained within; the luck of being able to taste it embodies a veritable gift, which a truly conscious individual must demonstrate of actually deserving.

Sunday, 4 April 2010

THE MILO FINE FREE JAZZ ENSEMBLE – The Untenability Of Sentience + More Wistful Tunes For The Sincere

Shih Shih Wu Ai

Milo Fine is as pure an improviser as we might hope to find. After having listened to his beyond-genre, untainted playing over a number of releases - especially on Emanem - I was very pleased to relish more of that spontaneous craft thanks to this item, a double whammy containing two live exhibitions that let us see different facets of this artist’s unlabelled sound world. Both CDs contain efficiently genuine instrumental sociability informed by a variety of creativeness that comes out unsoiled, not hyperbolical or, worse still, verging on the ridiculous. The records are issued on Fine’s private label and require firm concentration. This is not background stuff: the utmost attention is necessary to make a way throughout the various layers and catch the minute details that define the collective effort’s best traits.

The Untenability Of Sentience was recorded at the West Bank School Of Music, August 2009, by a trio consisting of Fine on M-drums II (electronics), piano, electronic piano, clarinets and voice, plus guitarists Steve Gnitka and Charles Gillett. The atmosphere that one breathes across an assortment of situations is prevalently exemplified by a state of extreme relaxation. The reciprocal listening is regulated by a significant attentiveness with rooms available for sixth sense, preferably transformed in unstinting gestural freedom. Clattering eruptions, unmanageable discharges and atonal ungrammaticalness produce constant surprise under the guise of shapeless electroacoustic matter, Gnitka and Gillett doing their best to maintain a semi-acoustic vibe through the usually polite, occasionally biting timbre of the axes. During short pauses we just hear the amplifiers’ hum, soon replaced by additional extravagant combinations of implausible sounds that, once locked together, appear as ideal complements to a play-now-forget-later kind of liberation. The highest point must be Fine’s hammering of the piano’s peak registers at the start of “87092”, which is invigorating to say the least: a cross of Nancarrow and a spastic version of Sergei Kuryokhin attributing further luminosity to an already brilliant performance.

More Wistful Tunes For The Sincere was captured on tape at Homewood Studios a month afterwards. Fine (drum set/bowed cymbals and clarinets) and Gnitka (guitar) are still in the party, this time with Scott Newell (tenor sax, voice) and Stefan Kac (tuba). This record tends to (hardly) justify the “Free Jazz Ensemble” name but don’t you ever think that hints to Ornette Coleman or Archie Shepp are going to be found. Basically, there’s a lot of high-quality interaction between the reeds when Fine decides to switch to clarinet and swap blows with Newell, and sturdily disjointed mayhem when the home’s owner goes back behind the drums, where he unleashes unsympathetic anti-patterns and eccentric rolls while the guitar/tuba/sax discussion becomes animated enough to recall - well yes – some pages of discordant jazz. Despite the innumerable parts in motion, the music always stays in the “unassumingly sane” pen (let’s pretend to ignore Newell’s willingly disconnected crooning); the anarchic sparkle that ignited the first CD’s restrained abstractions is a tad less vivid. On the other hand a tangible irony permeates the act, and what’s lost in impulsive lawlessness is instead gained in terms of hilarious blasts and revisionist – and not so wistful - “tunes”. Additional spots for Gnitka's virtuoso destruction of six-stringed common jargons and Kac's imperturbably lyrical serenity are also granted.

There are ways of sounding dissenting without appearing stupid – something that not all the self-styled “improvising musicians” on the market are able to achieve. These recordings show that on-the-spot inspiration, clever absurdity and a degree of internal sensibility work wonders in exploiting flexible structures inhabited by unblenching originality.


Elevator Bath

There are artists that look into the subconscious aspects of perception through plain coincidences generated by even simpler sonic architectures, achieving results that are unequivocally inimitable. Without a doubt, Adam Pacione can proudly stand among them. Dobranoc (Polish for "good night" - thanks, Adam!) comes on a limited edition picture disc – the vinyl is adorned with the artist’s experimental photographs - and constitutes an amazing illustration of his sound art, destined to generate extensive stretches of what I love calling “silence of the mind”.

The record contains two long segments, one per side, called “Dobranoc” and “Always”. Basically, not many differences subsist in their temperament, the impression of extremely gradual movement toward an inestimable stasis definitely felt throughout both pieces. Pacione utilized field recordings, guitars, shortwave radio, analog keyboards and Moog filters to craft the music, yet you’re not going to identify any of these instruments, as unremitting as your probing might be. What’s detected is only a massive accumulation of murksome clouds with very few openings, from which pale lights transpire amidst superimpositions of acutely poignant monochromatic harmonies. Frequencies that could induce someone to think of a concealed choir, quasi-frozen loops activating a sense of acquiescence to occurrences that can’t be possibly be controlled by our strength of character.

The spellbinding quality of these forward-inching masses makes sure that thoughts are left aside, and that any kind of overheated reaction is all but discarded. As the hiss, the unspoken throbbing and the private fluctuation set in motion by the composer’s vision keep smiling to uncompromisingness, we realize about the merits of this not-enough-lauded musician, a master of beneficial rational inertia.

Friday, 2 April 2010


Engine Studios

“All music derived from 22 numbered melody fragments, randomized and paired with visual, audio and narrative score structures”. I adore artists akin to Tom Abbs - here switching between bass, cello and tuba - who deliver a poor reviewer from the task of trying to explain how a creative model is conceived. Assisted by Brian Settles (saxes and flute), Jean Cook (violin) and Chad Taylor (drums), the leader gifts us with a singular variety of modern-yet-ancient “comprovisation” which takes into account prearranged machinations - frequently bordering on the minimalist side with a high percentage of grittiness - but pretty often sounds like classic free jazz, including a recording quality that pushes all the way back to the sixties.

Indeed the lucidity at work in the seventeen tracks of this album is tremendously concrete, all instruments behaving rather considerately and expressing without restraint at once. The compositional schemes appear to be a sort of excuse, something made to be respected first and broken later; but even when the music emerges a little bit hard-hearted, there’s always some kind of handgrip – a rhythm, a circular pattern - to which one can relate without getting lost. Each member’s improvising skills are top-rank, the ears gratified by technically advanced manhandling of commonplaces. Valuable stuff, needing quite a few spins for a thorough understanding.