A strong supporting player and striking soloist, Parker is one of few jazz bassists who regularly plays arco.
While Parker has been active since the early 1970s, he has had a higher public profile since the early 1990s. He is a vital musician in the New York City experimental jazz scene.
He has long been a member of saxophonist David S. Ware's quartet. Parker has recorded and performed with many musicians, including Cecil Taylor, Matthew Shipp, Daniel Carter, Peter Brotzmann, Bill Dixon, Charles Gayle, Roscoe Mitchell, Butch Morris, DJ Spooky and Mat Maneri.