S/D: singers who don't play an instrument

OK, roundup time: Iggy played guitar on several songs last time I saw him live ('93, American Caesar tour). David Thomas, in addition to accordion, played musette, plus a bit of soprano sax & even Theremin! Roger Daltrey played guitar on a few Who songs around the time of their (first) farewell tour in '82. David Yow played either bass or drums in the early days of Scratch Acid, before they recorded. Brad Delp is credited with acoustic guitar on Boston's first LP. John Lydon played some violin (?!) on "This is What You Want..."

Destroy: Jim Morrison, Henry Rollins (despite playing cowbell onstage during Black Flag's final days, according to Chuck Eddy)

And yes, Tod, Geezer Butler was the lyricist

Toots of Toots and the Maytalls, I think, is just the throat of reggae music.

But could not the human voice be considered an instrument of music? It does require some sort of formal or informal training to become manageable. Karaoke has given us vast insight to this conundrum.