[3] The group's self-described "dream music" explored drones and pure harmonic intervals, employing sustained tones and electric amplification in lengthy, all-night performances.
[5] Nonetheless, a bootleg recording removed from the archive by Young's first archivist, Arnold Dreyblatt, of a 1965 performance was controversially released in 2000 by Table of the Elements in CD as Day of Niagara.
Combined with Young's interest in sustained tones and Hindustani classical music was Tony Conrad's knowledge of just intonation and the mathematics of non-Western tuning, along with his introduction of electronic amplification.
[8] In 1964, the group began performing sections of Young's drone-based improvisational work The Tortoise, His Dreams and Journeys, which features a raga-like scale made up of the harmonic numbers 21, 189, 3, 49, 7, and 63 over the fundamental frequency.
[9] The Theater of Eternal Music's sustained notes and loud amplification influenced John Cale's subsequent contribution to The Velvet Underground in his use of both discordance and feedback.