Here is the acappella version of Michael Jackson's hit Another Part of Me. Pre-released for his Disney attraction Captain Eo and for the eponymous single and Bad Album.
On this track, only the words "Another Part of Me" and a few ab-libs(including "ooh ooh") were over-dubbed with his own background vocals. The rest of the track was done single-handedly!
Since you can still hear the Clave' Clap-Stick(also done be Michael Jackson), I wouldn't technically call it acappella. But more of the stripped-down variety(I wonder if there's a name for half-strippers?).
