As Chicago style jazz evolved from New Orleans jazz in the 1920s, one of its defining features was the addition of saxophones to the ensemble. The small Chicago ensembles offered more improvisational freedom than did the New Orleans or large band formats, fostering the innovations of saxophonists Jimmy Dorsey (alto), Frankie Trumbauer (c-melody), Bud Freeman (tenor) and Stump Evans (baritone). Dorsey and Trumbauer became important influences on tenor saxophonist Lester Young, who in turn had great influence on later jazz saxophonists. But the greatest influence of the saxophone on jazz was to occur a few years later when alto saxophonist Charlie Parker became an icon of the bebop revolution. The small-group format of bebop and post-bebop jazz ensembles gained ascendancy in the 1940s as musicians used the harmonic and melodic freedom pioneered by Parker, Dizzy Gillespie, Thelonious Monk, and Bud Powell in extended jazz solos. Saxophonists such as John Coltrane, Ornette Coleman, Sam Rivers, and Pharoah Sanders defined the forefront of creative exploration with the avant-garde movement of the 1960s. The saxophone remains prominent in jazz, soul, and funk bands today.