Just as any great artist defies and transcends convention, Joni Mitchell is a musician-poet whose inspirations refuse to be bound by genre. In the '70s she could have become the Picasso of pop-rock, with glittering multifaceted collections like For the Roses and Court and Spark, but she chucked that approachable - and predictable - style to pursue commercially risky jazz with The Hissing of Summer Lawns in 1975. After the darkly introspective Hejira and Don Juan's Reckless Daughter, came her smoky, but buoyant collaboration with the late jazz master Charles Mingus, simply called Mingus. This new double album is Mitchell's documentary of her 1979 tour, focused primarily on these more recent works. Shadows and Light was recorded at the Santa Barbara County Bowl and features 19 songs and some solo instrumentals. Unlike her recent LPs, it makes no artistic leaps. But these songs remind us that no other singer has dealt so eloquently and honestly with self-doubt, passion, betrayal and obsession as Mitchell. The real beauty of the set is Joni's sirenish soprano gliding along with dazzling sidemen like bassist Jaco Pastorius, drummer Don Alias, guitarist Pat Metheney, keyboardist Lyle Mays and sax wailer Michael Brecker. The marvelous Persuasions also chime in occasionally a capella. With this remarkable release, Mitchell proves she is a rare pop artist, stalking an ideal rather than an audience.