The Leslie speaker is a combined amplifier and loudspeaker that projects the signal from an electric or electronic instrument and modifies the sound by rotating a baffle chamber ("drum") in front of the loudspeakers. A similar effect is provided by a rotating system of horns in front of the treble driver.

Did the Beatles use a Leslie speaker?

According to Beatles biographer Bob Spitz, the effect enchanted John Lennon. ... The Leslie speaker was featured many times on Beatles recordings after that for vocals and instruments, although most famously on “Tomorrow Never Knows.” It remains one of the most well-known Leslie-aided records.

Did Jimi Hendrix use a Leslie speaker?

' The group also revisit “Tax Free” with Hendrix playing his guitar through a Leslie speaker on two of the takes; the later being marked as 'use.