A reviewer from a recent Peabody performance enlightening.

As a short introduction (for those unfamiliar with this phrase), avant-garde in music typically is defined by a lack of attention to a fundamental chord structure or rhythm. John Cage, after whom the Peabody Conseratory Avant-Garde Ensemble (CAGE) is named, was an American composer, best known for his piece “Four Minutes and 33 Seconds,” in which no instrument is actually played in the conventional sense. It is four minutes and 33 seconds of “silence,” making it a very controversial piece of contemporary music. As such, the avant-garde musical style embraces the unconventional and bizarre and pushes the limits of what can be even coined as musical expression.