TORONTO -- The Artist We Still Call Prince made a surprise appearance in a typically unlikely place: the all-female Lilith Fair.

Prince got up on stage during Sheryl Crow's set on the second of Lilith's two sold-out nights, Sunday, a spokesperson for Universal Concerts confirmed. He sang and played guitar on Crow's "Everyday Is A Winding Road".

According to one backstage source, the unscheduled guest spot "caught everyone off guard".

The impromptu appearance was also reported on The Artist's website and on the official Lilith Fair site.

Judging from comments in the alt-music.prince newsgroup, fans of the purple one were nonplussed by the seemingly oddball combination, with most posts either expressing surprise or engaging in a debate over Crow's artistic merits.

Coincidentally, Prince has a new album out this week under his own moniker. "The Vault", a 10-song collection of unreleased material recorded mostly in the mid-'80s, is being released by his former label home, Warner Music, with which he has had a very public, and very bitter, running feud over the rights to his master recordings.

Meanwhile, the night before his Lilith Fair guest shot, The Artist popped up during a set by Chaka Khan in New York.

According to his website, his next album is titled "Rave Un2 The Joy Fantastic" and will be released on an as-yet-undetermined major label this fall.