Prince, Bjork and Annie Lennox will all appear on that possibly previously reported Joni Mitchell tribute album ('possibly' previously reported because this all sounds very familiar, but I can't seem to find anything on it in our archives). The album is due for release this Spring, and the covers on it are as follows:
Sufjan Stevens - Free Man in Paris
Björk - Boho Dance
Caetano Veloso - Dreamland
Brad Mehldau - Don't Interrupt the Sorrow
Cassandra Wilson - For the Roses
Prince - A Case of U
Sarah McLachlan - Blue
Annie Lennox - Ladies of the Canyon
Emmylou Harris - Magdalena Laundries
Elvis Costello - Edith and the Kingpin k.d. lang - Help Me
James Taylor - River