Joni Mitchell was so thrilled with Vince Mendoza's arrangements for her last disc (for which he received a Grammy nomination) that she asked him to stay tuned for a double album of items from her long career as a songwriter. This hard-bound set features Mendoza versions of 22 Mitchell songs, from the Circle Game to Sex Kills to Otis and Marlena. Mendoza is a thorough craftsman, as is producer Larry Klein, and the two have spared no effort to provide lavish backgrounds for Mitchell's still arresting voice. But lavish doesn't suit songs like Woodstock or Cherokee Louise, in which Mitchell's clear-eyed musings about a Manhattan street person are made to sound ridiculously out of touch. Mendoza's versatility - he can do lounge, he can do cool jazz, etc. - is contained within a default idiom that suggests a late remake of Mr. Copland Goes to Hollywood. A few deft items - check out the smooth lounge treatments of Be Cool and You Dream Flat Tires - can't save a set in which so many fine songs are not merely covered, but euthanized.