The Essential Philip Glass is a three-disc 2012 compilation not to be confused with the single-disc 1993 album, The Essential Philip Glass. The tracks from both are taken from previous Sony releases. Two of the discs of the 2012 set are made up of single tracks from a number of albums, including Songs from Liquid Days, Glassworks, the film score Naqoyqatsi, the ballet In the Upper Room, and the choral-orchestral piece Itaipu. Stylistically the music represents a fairly narrow range in Glass' career; all the music except for Naqoyqatsi is from the 1980s. There is variety in the musical forces used; the Philip Glass Ensemble led by Michael Riesman figures prominently, but there are also pieces that use chorus, vocalists, and piano. Linda Ronstadt, Yo-Yo Ma, the Kronos Quartet, and Glass himself are among the distinguished soloists. The third disc was originally released in 1987 as Songs from the Trilogy and is made up of brief selections from Glass' three portrait operas, Einstein on the Beach (1976), Satyagraha (1980), and Akhnaten (1983). This disc includes mostly truncated sections of the operas rather than complete scenes. They give a good idea of what the music sounds like, but because they are cut so short they fail to create the kind of extended temporal experience Glass intended. The excerpts from Einstein are especially welcome, though, because they represent a very different side of Glass' creative personality from the other pieces. The performances are consistently topnotch. Sony's sound is exemplary throughout.