Great albums, I often think, are those that are capable of summoning a universe. Some, such as Sgt. Pepper’s, paint a vivid image of a specific point in time – giving the impression that the picture brought to mind is 1967, in one fashion or another. Rarer still are the albums that, rather than depicting a given moment, come to create a world that had only ever existed in the mind of the musicians.

Part of why I am so interested in plunderphonics – that is, music built almost entirely from pre-existing samples – is that it is forced to straddle these two categories in an almost paradoxical manner. At once every part of the record is tied, via the source sample, to a particular instant in time, and yet the end result depicts none, or perhaps all, of them. The band behind it, dependent entirely upon the artists before them, can nevertheless succeed in producing something that is unmistakably their own.

The Avalanches’ debut album Since I Left You falls in the middle of what has widely come to be regarded as the holy trinity of plunderphonics

The Avalanches’ debut album Since I Left You (or SILY), which reached its 20th anniversary this week, falls in the middle of what has widely come to be regarded as the holy trinity of plunderphonics: DJ Shadow’s Endtroducing… preceded it in 1996, and J Dilla’s Donuts followed in 2006. Produced over a few years by a ragtag group of Australian DJs - watching a clip of them pissing about on TV in the ’90s, it seems ridiculous to think that they would produce one of the most singularly brilliant albums ever only a couple of years later - the style of SILY stands apart even from these; while the other two ultimately base themselves heavily within the hip-hop idiom, the Avalanches’ setting is essentially one of a nightclub. On a basic level, the tracks, diverse though they are, remain constantly danceable, constantly fun.

Yet there is always something slightly disquieting about the unbridled joy of the album, I suppose because it manages to lie outside of time; certainly it feels as though it is from the past, but beyond that, the album’s nature ensures that any timeframe is impossible to pin down. It’s as though it is from a past that never existed, similar to our own but slightly different, in which all its elements coexisted – one in which Raekwon rapped over ’60s easy-listening guitar, in which a Latin organ played behind an American comedian at Club Med, in which the Osmonds became something ethereal.

There is a convention of sorts in plunderphonics that the best samples are those that are unexpected, obscure, fresh; in the words of band member Darren Seltmann, “the more rejected and unwanted the record that a sample comes from, the more appealing it is”. When one considers how many of the samples are only a few seconds long, I suppose there is a sort of principle underlying this: while great albums are rare, and great songs are hardly easy to generate, most groups will produce a few great seconds buried deep within a record at some point, if only by accident. In a perverse sense, great music is no doubt frequently happened upon by musicians, if only for a few moments at a time; to locate these by ear, to stitch them together into something far beyond the original songs, is the art of this genre.

The unrecognisability is almost an end in itself, and not only for legal reasons; tracks based on readily identifiable songs can often drag up unintended associated emotions that conflict with the producer’s intentions. For my part, of SILY’s alleged thousands of samples, faint glimmers of recognition arose only four times: for the bassline from Madonna’s Holiday, the chorus from the disco hit Stool Pigeon, some violins from Walton’s Spitfire Prelude, an isolated sample of Francoise Hardy. However, a few guideposts are almost welcome, since they remind the listener of the way the music was produced, something which can almost be lost amidst slick production. Late in the album, when Hardy suddenly cuts orthogonally across an incongruous rhythm section, it evokes a sort of Brechtian distance from the music, calling to mind the artifice inherent in it, the nonexistence of what it seems to depict.

If one wanted to produce an album to represent the end of a civilisation, I like to think that plunderphonics would be the natural genre.

If one wanted to produce an album to represent the end of a civilisation, I like to think that plunderphonics would be the natural genre. Not unlike the barrage of quotes that closes Eliot’s world-elegy The Waste Land, a musical closing statement would have to be looking backwards, engaged in piling up such fragments as are shored against our ruins. The end result would be a chaos of our own design, self-aware of its form but the overall emotional impact would not be fixed. If Endtroducing… is a murky inferno, and Donuts a kind of purgatory, then, as its title track declares, Since I Left You can welcome us to paradise, if only for an hour. Certainly it is an ending, but it is one of celebration.