William Parker (1952) is an American free jazz double bassist, multi-instrumentalist, poet and composer. With his wife, dancer Patricia Nicholson, Parker founded the Improvisers Collective, an organization that presented free jazz in combination with other types of spontaneous performance. Parker's style is based on a tradition of self-expression and experimentation. His arco work is possibly the most fascinating aspect of his idiom; Parker excels at the creation of dense, hyperactive streaks of color, gleaned from the inherent harmonic properties of the instrument. At bottom, he is a textural player. Lyricism plays a secondary role in his work, with or without the bow. Parker's pizzicato style is overwhelmingly percussive, in intent and effect.