At least once every Schatzy performance, Greg Schatz jumps off the stage and makes his way through the crowd. But even as he leaves the bandstand, he takes the music with him. Schatz fronts the band that bears his name, and as he winds through the club he pushes and pulls on the bellows of his instrument, sending air over the reeds and music between the people who fill the room and the street outside. The sound is seductive, but with a pulse—something like a piano crossed with a horn, only th...