This 1990 acoustic performance shows that Tesla was a hair band in name only. For 75 minutes, the California hard-rock quintet runs through a scintillating selection of originals and well-chosen covers in one of the very first acoustic concerts before MTV's Unplugged became all the rage. The ragged video quality adds to the homey, intimate atmosphere the band creates sitting on stools in a small Philadelphia club surrounded by hundreds of rabid fans. Along with songs off its first two albums--including "Modern Day Cowboy," "The Way It Is," a...