such as Karlheinz Stockhausen, regularly experimented with magnetic tape and musique concrète techniques. The Beatles each prepared loops at home, and a selection of these sounds were then added to the musical backing of "Tomorrow Never Knows". The process was carried out live, with multiple tape recorders running simultaneously, and some of the longer loops extending out of the control room and down the corridor. The inclusion of reversed tape sounds on "Rain" (specifically, a portion of Lennon's vocal part) marked the first pop release to use this technique, although the Beatles had first used it, in some of the tape loops and the overdubbed guitar solo, on "Tomorrow Never Knows". The backwards (or backmasked) guitar solo on "I'm Only Sleeping" was similarly unprecedented in pop music, in that Harrison deliberately composed and recorded his guitar parts with a view to how the notes would sound when the tape direction was corrected. Experimentation with backwards sounds was a key aspect of the Revolver sessions, as was the use of the Leslie speaker effect. The band's interest in the tones that resulted from varying tape speed (or varispeeding) extended to recording a basic track at a faster tempo than they intended the song to sound on disc. During the sessions, Emerick recorded McCartney's bass guitar amplifier via a loudspeaker, which Townsend had reconfigured to serve as a microphone, in order to give the bass more prominence than on previous Beatles releases. Although this particular technique was used only on the two songs selected for the May 1966 single, an enhanced bass sound was a feature of much of the album. Emerick also ensured a greater presence for Starr's bass drum, by inserting an item of clothing inside the structure, to dampen the sound, and then moving the microphone to just 3 inches from the drumhead and compressing the signal through a Fairchild limiter. MacDonald writes that, despite EMI Studios being technically inferior to many recording facilities in the United States, Starr's drumming on the album soon led to studios there "being torn apart and put back together again", as engineers sought to replicate the innovative sounds achieved by the Beatles. The preference for close-miking instruments extended to the orchestral strings used on "Eleanor Rigby", to achieve McCartney's request for a "really biting" sound, and the horns on "Got to Get You into My Life". This was another break from convention, and