Which musician retired too soon?

Grace Slick comes to my mind. Her voice, lyrics and capacity to rock, or sing a ballad made her one of the few greats of the 60's-70's. Of course Cat Stevens, but he has released new music. It's just not the same genre of his famous past.
By the way, I always enjoyed Eric Burden. Has anyone heard his last release and want to comment on it?

Could you imgine what Frank Zappa would be doing today?

These are not individuals, but for rock 'n roll bands I'd nominate Buffalo Springfield (and, of course, that group Paul McCartney was in during the 60's : )

I'd include Peter Green and Artie Shaw;
even though Green has returned recently.

And the list of those prematurely "retired"
by substance abuse or accidents is WAY too
long. A few favorites not mentioned yet are
Gram Parsons, Clarence White, Clifford Brown,
Buddy Holly and Stevie Ray Vaughan.

Artie Shaw, who retired because he felt the music industry was strangling his creativity.