yes, joni mitchell sat in with the mothers, on november 13th, 1970, at the fillmore east in nyc.
"joni mitchell sat in with us last night during the second show and we
improvised a thing that was really good. and
we ended it with her singing 'duke of earl'.
really far out, she came on stage: 'now ok and we're going to improvise
this thing...' and we did a few chords for her and she started reciting this
poem which began: 'penelope wants to fuck the sea..."
and the audience did a double take 'yuuunk!'... a little hush falls over
the fillmore... joni mitchell?"
-zappa, 1970 (source: miles)
yeh, i was at that show when mitchell improvised a tune about a girl who wanted to fuck the sea. while she tried to be ethereal and haunting, zappa made the band alternate 2 monster chords a tritone apart at an ominous largo tempo. mitchell looked a little thrown by this and glanced over at zappa, as if she wasn't expecting him to lob her a curve ball.
i´ve read somewhere that she showed up at least once at zappa´s place in the late 60´s. seems a very strange connection to me (was she wearing feathers and bells?)
even stranger was that she dated motorhead, which is why she ended up at frank's place...
charles ulrich (firstname.lastname@example.org)
1. joni mitchell was motorhead's "strange new girlfriend", circa 1967.
2. she sat in with the mothers at the fillmore east on 11/13/70.
the persuasions perform on joni mitchells 'shadows and light' album. great band she has on that album, jaco pastorius, pat metheny, lyle mays, don alias and michael brecker.