Johnson was the director of the UT Early Music Ensemble, one of the largest and most active in the U.S., from 1986-2003. In 1998, he was awarded Early Music America's Thomas Binkley Award for university ensemble directors. He is also the recipient of the 1997 Quattelbaum Award at the College of Charleston. Johnson teaches master classes in performance practice and also serves on the faculty, staff, and the Executive Advisory Board of the Amherst Early Music Festival. He has been on the faculty of the Texas Early Music Workshop [aka Texas Toot] since 1994 and has been its director since 2002.