Currently, it is capable of reconstructing a performer's style of playing a specific work, from a recording of the work, and can be used to rebuild flawed recordings. It cannot yet play a new piece in a performer's style, though the developers are planning to work on that next.
“It introduces a whole bunch of interesting intellectual-property issues, but eventually, you ought to be able to, in essence, cast your own band,” said Frey. “You should be able to write a piece of music and for the drum piece, have Keith Moon, and for the guitar piece, you can have Eric Clapton — that is a derivation of understanding each of those artists’ styles as a digital signature. That’s further down the road, but initially, you’re going to have the ability for artist to create music and have the listener manipulate how they want to hear it — [for example] sadder.”The intellectual-property implications alluded to are interesting; the prospect is raised of a new type of copyright, over an artist's style, being created, with the artist or their estate collecting royalties from replication of their style. While this is perfectly consistent with the copyright-maximalist ideology of the corporate-dominated, post-industrial present day, it ignores the fact that artists emulate other artists all the time. While initially, courts would exercise "common sense" and leave non-software-based copyists alone (i.e., Oasis wouldn't owe licensing fees to the Beatles), sooner or later, once the technology becomes the norm, this original intent would be forgotten and, after a few strategic court cases, a new precedent would be set, declaring styles, and the elements of them, to be licensable, much in the way that patents are, and requiring anyone taking them off to license them, much as anyone sampling even a split-second of a recording has to license it. (In the age of powerful rights-licensing corporations with political clout, intellectual-property law is a ratchet that turns only one way.) Soon, the different elements of musical style would end up aggregated in the hands of a few gigantic rightsholders with well-resourced legal teams, and musicians would be routinely slugged with heavy bills, itemised by stylistic elements.
Unfortunately, these hypothetical questions tend to be answered in the favour of whomever has the most powerful lawyers and lobbyists, i.e., the intellectual-property barons. Witness the minefield of software patents and resulting cross-licensing oligopoly that has occurred, for example.
The invention is useful for the copyright debate because it is like the hypotheticals that philosophers use to illuminate questions. So, what is it to "write" a piece of music? At what point is one copying? George Harrison was sued for copying "He's So Fine". In that case the notes in two melodies were considered too similar. But thousands of bands have emulated the Beatles in many different ways, without being sued for being too similar. The band Kiss got the idea for wearing consistent costumes from the Beatles. Many musicians have said that they were inspired to form a band when they saw the Beatles on TV. At what point is it copying? ... Now if I wrote a song and got software to play it in the style of Clapton, what would the software do? It must change the notes - is it still my song? If someone else ran the software over my song, should I or Clapton sue? What is that I wrote - a chord progression? Thousands of pop songs share the same few chord progressions, with superficial stylistic differences ...