Philip Glass Piano Etudes : The Complete Folios 1-20

A handsome, informative new folio collection of the études — edited by the composer-performer Timo Andres and Cory Davis from Glass’s publisher, Dunvagen Music — has just been packaged with “Studies in Time,” conceived by Pomegranate Arts, producers long associated with Glass, and published by Artisan.

It’s an unexpected landing for a project that started as personal exercises. But today, the études are spoken of in the same breath as those by Chopin and Debussy. And their influence extends beyond the world of keyboard playing. “Studies in Time,” edited by Linda Brumbach and Alisa E. Regas of Pomegranate Arts, includes surprising contributions from, among others, the filmmaker Martin Scorsese, the artist Maira Kalman and the chef Alice Waters.