2006 UTC I can t see anything aleatory about the Books style either They use a lot of samples in their music and there is always a chance element when working with processing and such i e you don t really know how the clip is going to sound when you reverse it until you ve done it This isn t aleatory though I guess it would be closer to musique concr te In any case I don t think that the Books belong here This is a slightly different topic but I think that the distinction between Boulez and Cage on this page is unclear Cage didn t use the term aleatory as far as I know and their conflict had to do with intention vs nonintention Perhaps a more neutral technical definition not immediately connected with a composer could start the music section followed by a brief list of a few composers and representative works and a link to the longer article on aleatory music Unless there are any objections I ll do that soon 09 16 1 February