Various Artists

The roster of artists assembled here — Caetano Veloso, Elvis Costello, Emmylou Harris, Prince, etc. — would make even the most casual Joni Mitchell fan tingle with curiosity. But the sense of "what would that song sound like done by this person?" dissolves as song after song stalls under the weight of its new host's personality. Everyone who appears has created an oeuvre in his or her own right, which, believe it or not, ends up backfiring. Most attempt to make these songs their own, which proves to be a daunting prospect if there ever was one. In this context, for example, Björk and Sufjan Stevens' whispery meekness comes off as aggressively pretentious. At the same time, the sacrilegious changes they make to their respective songs is offset by their ambition and obvious admiration for Mitchell's work. Brad Mehldau, for instance, pulls off a Houdini-like feat by recasting a Mitchell gem as a solo piano piece and taking it to new realms without sullying its beauty. And k.d. lang — perhaps the smartest of the bunch — plays it safe with only slight changes to the song "Help Me" and comes up with a gorgeous rendition of her own. All in all, this disc serves as a great vehicle for Mitchell fans to get together and for the uninitiated to acquaint themselves.