The Stones recorded this after the death of Brian Jones
but before Mick Taylor joined the band as his replacement. As a result, Keith Richards played both acoustic and slide electric guitar, and Bill Wyman played bass and autoharp. Autoharp is a string instrument with a series of chord bars attached to dampers which, when pressed, mute all but the desired chord. An autoharp is not really a harp - it's a zither.
Bertrand - Paris, France