When the composer John Cage was beginning to conceive of a new, all-encompassing approach to music that was to become epitomised by his 1952 piece 4'33", he was probably unaware of Alphonse Allais's Funeral March for the Obsequies of a Deaf Man, a musical composition dating from 1897 and consisting of 24 blank bars. He was also probably happily oblivious of the In futurum movement of Erwin Schulhoff's 1919 piano work Fünf Pittoresken, a score consisting entirely of meticulously notated rests.

These precursors in no way detract from Cage's achievement: to put it somewhat crassly, they were eyebrow-raising novelties (in the best possible sense), while 4'33" was a watershed not just in music but in art. The difference between them is the ideas they express: dadaist whimsy in Allais and Schulhoff, a rethinking of our notions of what music is in Cage (though Cage was himself no stranger to whimsy, dadaist or otherwise). 4'33", unlike these precursors, is defiantly not about silence (Cage's experience in an anechoic chamber convinced him that there was no such thing) but about creating a context in which to listen, to consider the stuff of music – sound. Cornelius Cardew summed up the Cageian philosophy: "Sound becomes music because of the way you listen to it." It can perhaps be said that Cage used the same technique as these earlier composers or, at a stretch, that he appropriated the same intangible material (that of an absence of conventional musical sounds). The intention of the piece, however, is utterly different. Does this matter if the effect of Funeral March or In Futurum in performance is the same? I think so. Before 1952, these pieces were musical vacuums: it is only in a post 4'33" world that these pieces can be heard (even if their composers didn't intend them to be).

There are many examples of artists unconsciously treading on the toes of their forebears and it is perhaps comforting that what appear to be some of the more remarkable feats of imagination are often not without precedent but rather, like 4'33", a refinement of an idea, transformed beyond recognition by the artist's vision. But of course, artists have been knowingly pilfering others' work for centuries too. Such pilfering dates back to the earliest days of western music and achieves its most obvious state in the form of the "theme and variations" in which a composer would cull a melody from another and let their own creative drive take over, transforming it and mining it for all it was worth.

Composers in the 20th century rather fell out of love with the theme and variations and using borrowed material became swampier ground, the distinction between the "found" material and the composer's own language distinctly hazier. Cage's approach set him apart. Take his piece Cheap Imitation of 1969. Here, the rhythmic structures of Erik Satie's Socrate are retained while the melodic pitches are reordered using chance techniques. Only this reordered melodic line remains and the result sounds like a sort of vague, half-remembered Satie, bracing in its austerity. In the set of Harmonies, from his larger work Apartment House 1776, Cage takes American hymn tunes from the time of the revolution and either subjects notes to chance-determined extension/diminution, thus smearing the previously clear cut harmonic language, or deletes notes entirely, decluttering it of its 18th-century tropes. The role of the composer here is much closer to that of editor, changing (or "correcting") the material, bringing the hymn tunes into line with Cage's tastes (something the composer found slightly uncomfortable as his work up until this point attempted to eschew the ego of the author). The whole of the borrowed work is presented, just devoid of some of its defining features.

Cage's most acknowledged legacy in the broader arts world lies in the Fluxus movement of the 1960s but artists today are still drawn to these ideas. Parallels may be drawn between Cage's technique in the Harmonies and that of the Swiss visual artist and comedian Ursus Wehrli. Wehrli's shtick is that art is "messy" and, as such, his work represents a long-overdue attempt to "tidy it up". So, when presented with a piece of mid-20th century abstraction, he separates all the elements of the image and arranges them by type into neat stacks (though his rigour sadly neglects him when it comes to Jackson Pollock). A crowded Bruegel street scene becomes eerily empty of life while the floorspace of Van Gogh's bedroom is cleared, all the detritus being stored on top of, and underneath, his bed: it's dadaist whimsy a go-go, certainly, but also recalls the Cage of the Harmonies. I'm not going to make any great claims for Wehrli as an artist – the work is fun, which is surely its guiding principle – but he certainly brings his own fastidious vision to these paintings: the works are strangely familiar but speak with a new (Swiss) accent. He also demonstrates the breadth of influence that Cage has had. What other composer has had an influence on comedy? Eric Morecambe could have been describing Cage's methods when he claimed to be "playing all the right notes, just not necessarily in the right order".

Wehrli is an artist whose use of found material and intervention is transparent (and indeed relies on this transparency). Some rather fusty critics may take umbrage at his playful deconstruction of the canon but his working methods are nowhere near as potentially controversial as those of the poet Kenneth Goldsmith, one of the most striking contemporary writers. Goldsmith's works rely on transcription; pure, verbatim transcription. For example, his 2003 book Day consists of all the words, letters and numbers that appear in the 1 September 2000 edition of the New York Times. The idea of this work is to disassociate the reader from the original context of these words, to reframe the experience of reading a newspaper. In so doing the reader's attention is focused, not on the information the words were originally there to impart, but on the sound and rhythm of the language. Perhaps you've already spotted the similarities between this approach to language and Cage's approach to sound? The reader or listener – the "intelligent agent", as Goldsmith generously dubs us – becomes a conduit through which the work is created: they are, in fact, vital to the artistic process. The idea of the dormant, unread, unseen or unheard artwork has no place here: the act of performance is an act of creation in communion with the audience. Consider that Cardew comment again, that "sound becomes music because of the way you listen to it". If we were to substitute "sound" for "words" and "music" for "poetry", then I think we have a pretty good creed for Goldsmith's artistic approach, albeit one with slightly eccentric grammar.

This kind of working method, labour intensive as it is, does open the artist up to charges of plagiarism, but Goldsmith asks the question "what's wrong with that?" If it's a question of skill then this misses the point of what art is surely about. Art doesn't have to blind us with virtuosity to make us think or feel. And what in the world isn't "found" material? If most artistic endeavour can be seen as a selection and reorganisation from a limited pool of material (the words of a language, the gradations of colour on the spectrum, the notes of a scale) then the answer is not very much. Who was the last person to create the stuff of which their art is made? And does it really matter? The shuffling of these finite elements has, throughout history produced an unimaginable number of unique works (I'm reminded of the books that make up Borges's "Library of Babel"). "We don't need the new sentence, the old sentence reframed is good enough," claims Goldsmith.

So, in 2014, Cage's 102nd year, his ideas are still relevant and vital to contemporary culture: Wehrli and Goldsmith are by no means exceptions in drawing inspiration from him. His centenary year inevitably saw a great outpouring of critical discourse and he is, I think it's uncontroversial to say, one of the most important artists, let alone composers, of modern times. Perhaps it's all been said before. But then... hasn't everything?