Thomas Marshall has been an instructor at the College of William and Mary for 22 years. He has also served for more than two decades as harpsichordist for the Colonial Williamsburg Foundation where he has performed numerous works of the concerto grosso style in original orchestrations, on original instruments. He is featured on many of the historical recordings issued by the Foundation.
A longtime member of the American Guild of Organists, he has served as organist for the Williamsburg United Methodist Church since 1977. He performs frequently with the Virginia Symphony, numerous baroque chamber ensembles, and organ and harpsichord recitals throughout the United States and Europe. He has made seven study tours in Europe to examine and play many surviving keyboard instruments from the 15th to the 19th century.