Complex sentence: He remained in Otis band until 1959 when he formed his own group, The Jimmy Nolen Band, performing in small clubs and ballrooms in California and Arizona's "Chittlin Circuit", backing many of the blues greats that passed through California.
Split into simpler sentences: He remained in Otis band until 1959 when he formed his own group, The Jimmy Nolen Band. They performed in small clubs and ballrooms in California and Arizona's "chitlin' circuit", backing many of the blues greats that passed through California.