Knock-knock. Who's there? Knock-knock. Who's there? Knock-knock. Who's there? Why, it's Philip Glass!
Not many composers have their own knock-knock joke, but then Glass is a two-note auteur of self-described "music with repetitive structures." This 10-disc doorstop-size box set is deftly constructed to showcase Glass' repetitive singularity and formal diversity; no composer dines out as frequently at the opera house, the symphony and the Cineplex, so there's everything from early compositions like 1969's "Music in Contrary Motion" to the opera Einstein on the Beach to a full disc of Glass' recent collaborations with the Kronos Quartet. All of the choices show off the evolution of Glass' technique, as well as its sneaky breadth; repetition may be a big part of his power, but so are surprising moments of ecstasy.