The gospel of Philip …

… Article— Philip Glass Half Full — Commentary Magazine.

Revealingly, it was not a composer but an avant-garde playwright, Samuel Beckett, who served as his main source of inspiration. Like so many of his contemporaries, Glass was “feeling the exhaustion of the romantic principle” that had hitherto driven the story-based dramas of Arthur Miller and Tennessee Williams. For him, traditional classical music was also a storytelling art, one that uses tonal harmony to articulate and propel large-scale “narratives” that unfold over time. But Glass aspired to write music that would be similar in effect to Beckett’s Waiting for Godot, in which scene follows scene in a way that bears no resemblance to the tightly wrought plot of a conventional play. Such a music, as he explains, would have “the coherence of rationality without the logic,” instead offering its listeners “an emotional high that came from being detached from the world of the rational and the dramatic.”

I heard a piano concerto of Glass's in concert once (I don't know if he's written more than one). It was  a moderately pleasant interval of noodling.