Alexei Lubimov and Natalia Pschenitschnikova have one of the best John Cage recordings, As It Is, and I'm glad ECM is on Spotify, as I have no idea where my CD is and I've given up on MP3 files via iTunes.
Not sure if it's a new recording or just a re-packaging, but I'm also listening to John Cage's Variations IV. As always, except for his piano music from the 1940s, it's never obvious what Cage is trying to do. The sounds are interesting even if the organization still doesn't make any sense to me. The chugging and Christmas music in Excerpts - 9pm to 10pm are unpleasant. Here's the process for this work:
As in the earlier Variations pieces, the materials here are transparencies (1 sheet with 9 points and 3 small circles) and a short written instruction. All points and circles are cut up for the creation of a program; 7 points and 2 circles are needed, which are all (except for one circle, which is placed anywhere on the map) to be dropped on a map of the performance space, creating places where actions might be performed. Lines are drawn from the placed circle to the points. The second circle is only used if one of the lines intersects it (or is tangent to it). The result is a graphic representation of where sounds may occur. Cage indicates that sounds may be produced inside and outside the performance space. There are no indications of durations, dynamics, etc.
Not much of La Monte Young's music on Spotify. I have the DVD of The Well-Tuned Piano, which is the canonical work. The composer's work on Spotify is sparse and transposed music for guitar is not as satisfying. The Ambient Century playlist has four tracks, including one from Noël Akchoté (who records more diverse music than any other guitarist in the world).