Saxophonist and composer Steve Lehman makes use of spectral harmony on his album Travail, Transformation and Flow (Pi Recordings, 2009). The result is a carefully crafted and emotionally engaging exploration of the physics of sound, played by a group of musicians who are seeking new ways to make improvised music. In this interview, Lehman offers a crash course in spectral harmony; discusses his compositional style and why he chose the particular musicians on the album; and talks about the influence on his life and music of Jackie McLean and Anthony Braxton.