One of the divergent trends of the swing era was a resurgence of small ensembles playing "head" arrangements, following the approach used with Basie's big band. The small band format lent itself to more impromptu experimentation and more extended solos than did the bigger, more highly arranged bands. The 1939 recording of "Body and Soul" by Coleman Hawkins with a small band featured an extended saxophone solo with minimal reference to the theme that was unique in recorded jazz, and which would become characteristic of bebop. That solo showed a sophisticated harmonic exploration of the composition, with implied passing chords. Hawkins would eventually go on to lead the first formal recording of the bebop style in early 1944.