 These records placed a musical emphasis on timbre and texture over meter and harmony, employing a wide variety of electronic instruments and innovative percussion instruments, including the electric celeste, Hammond B-3, bass marimba, harp, and timpani.As result, Sun Ra proved to be one of the first jazz musicians to explore electronic instrumentation, as well as displaying an interest in timbral possibilities through his use of progressive and unconventional instrumentation in his compositions.The title song of Charles Mingus' "Pithecanthropus Erectus" contained one improvised section in a style unrelated to the song's melody or chord structure.