At CU Boulder, Lewis also leads the graduate program in orchestral conducting including both the masters and doctoral level. His former students are currently enjoying success as conductors with professional orchestras and opera companies, university and school ensembles, and youth orchestras. 

Prior to his appointment at Colorado, Lewis served on the faculties of Texas Tech University, The Ohio State University, The University of Michigan, and Abilene Christian University. He is equally at home with professional, university, and youth ensembles. He is the Principal Guest Conductor of the Boulder Philharmonic and has appeared with the Colorado Symphony Orchestra, the Sichuan Philharmonic Orchestra (Chengdu, China), the Colorado Music Festival, Boulder Ballet, Midland Ballet Theater, Ballet Lubbock, the Lubbock Symphony Orchestra, the Abilene Philharmonic Orchestra, the Quad Cities Symphony Orchestra, the New Symphony Orchestra (Sofia, Bulgaria) and the Western Plains Opera Theater. His work with summer music festivals has also been noteworthy including the Interlochen Center for the Arts, Pine Mountain Music Festival (opera and symphonic) and Rocky Ridge Music Center.

As a strong advocate of music education, Lewis has presented many in-service workshops for public school educators, as well as numerous presentations at state and regional music education association conferences. In addition, he has conducted All-State Orchestras and Bands in many states along with the ASTA National Honor Orchestra and the Honor Orchestra of America. In 2010 Lewis became the founding Artistic Director of the Greater Boulder Youth Orchestras and continues to serve as conductor of the Symphony Orchestra.

Lewis is also a strong proponent of new music. He has been instrumental in the development and production of contemporary music festivals and his interest in new music has led him to collaborations with composers such as Dan Kellogg, Carter Pann, George Crumb, William Bolcom, John Harbison, Chen Yi, Michael Daugherty, Stephen Paulus and many others.

As well, his weekly “Boonshaft’s Blog” for music educators continues to inspire teachers everywhere.  He has received official proclamations from the Governors of five states and a Certificate of Appreciation from former President Ronald Reagan, as well as performing for former President and Mrs. George H. W. Bush, former President Bill Clinton, and for Margaret Thatcher, former Prime Minister of the United Kingdom.  His honors also include being selected three times as a National Endowment for the Arts "Artist in Residence,” three times awarded Honorary Life Membership in the Tri-M Music Honor Society, receiving the Al G. Wright Award of Distinction from the Women Band Directors International, and being selected for the Center for Scholarly Research and Academic Excellence at Hofstra University in Hempstead, NY, where he is Professor Emeritus of Music.