Steve Lacy used to say that the right partner can help you make music you couldn't get to by yourself. Take the quartet William Parker founded in 2000, for example. Parker's bass tone was always sturdy as a tree trunk, but power drummer Hamid Drake gives him lift. The upshot is that free jazz can swing, too. The quartet's front line is another firm partnership: quicksilver alto saxophonist Rob Brown and flinty trumpeter Lewis Barnes.