As a soprano and tenor saxophonist, Tillis performs music in the jazz and other African American traditions throughout this country and the world. As well as residencies, he has travelled with the Tillis-Holmes Jazz Duo, the University of Massachusetts Chorale, and the Tradewinds Jazz Ensemble to Australia, China, Estonia, Fiji, Greece, India, Japan, Mexico, New Zealand, Poland, South Africa, the former Soviet Union, Thailand, and Turkey. Tillis has also made numerous solo and group recordings including Festival Journey Concerto (1999) with Max Roach and the New Orchestra of Boston, Freedom (1996), The Second Time Around (1991), Paintings in Sound (1990), Contrasts and Diversions with the Tillis-Holmes Jazz Duo (1987), and Among Friends with the Billy Taylor Trio (1992), and Portrits from Gerswin's Porgy and Bess, with Tillis-Holmes Duo and Friends (quartet).