Bobby Watson, Ed Jackson, Rich Rothenberg and Jim Hartog make up the band that stole the show during the day-long “Music is an Open Sky” Festival (sez the New York Times, and we agree). Combining original James Brown/Motown dance rhythms with sophisticated harmonics and fire of bebop they succeed at the difficult task of creating music that is interesting and popular, free and swinging without a rhythm section. Daring arrangements pay tribute to the masters — Monk (“I Mean You”), Bud (“Un Poco Loco”), and Bird (“Conformation”), invoking their spirits without imitating, and introduce new originals.