Recorded in 1993, Stone of Sisyphus didn't appear as scheduled in 1994 due to Chicago's record label, Warner, believing the album to be too uncommercial. As it often happens with unreleased records by major acts, a legend built up around the scrapped record, at least among devoted Chicago fans, the kind who would appreciate the musical stretching found on Stone of Sisyphus. Frankly, they may be the only group to appreciate the departures on Stone of Sisyphus, as it's a curious creature - a splashy, expensive mainstream album that's restless yet not quite experimental but entirely devoid of pop songs. If this had been the Chicago of the early '70s, who specialized in ten-minute jazz-rock songs on their series of double albums, perhaps it would have been easier for the label to accept the variety of sounds here, but this was a Chicago coming out of five years of big placid adult contemporary hits…