His compositions are published by Paraclete Press, Aureole Editions, Holbrook & Associates, and Birolius Editions. Compositional commissions have included The Shout, an anthem for St. Paul's Episcopal Cathedral, Oklahoma City; and Each Ray of Light, an anthem for St. Andrew's Presbyterian Church, Beaumont, Texas. His earlier recording of his completion for Bach's Contrapunctus XIV on the Pipedreams Premieres compact disc is available from the Pipedreams® website.
Since 2016 he has been Organist of St. Rose of Lima, in Roseville, Minnesota. Previous appointments have been as Organist of the Church of the Immaculate Heart of Mary, Minnetonka; Associate Organist of St. Olaf Catholic Church, Minneapolis; Music Director and Choirmaster-Organist of University Baptist Church, Minneapolis; Choirmaster-Organist of St. Paul's-on-the-Hill Episcopal Church, St. Paul; and Sub-Organist, Cathedral of St. Paul, in St. Paul. He teaches organ, piano, music theory, and composition privately.
He has collaborated with noted chant scholar Bruce Ford on various projects, adapting Gregorian chant to English words according to authentic principles of Gothic musical art. His researches on the chant have taken him to St. Mary's Convent, Wantage, Oxfordshire; and to several years of study with Jean Langlais, with emphasis on the use of chant in composition and organ improvisation, as exemplified in the works of Cesar Franck, Charles Tournemire, Maurice Duruflé, and others.
He was featured as organist and composer at the 1991 national convention of the Association of Anglican Musicians. In 2000 he performed a solo organ recital at Westminster Cathedral, London, featuring movements from Bach's Art of Fugue. Also in 2000, he performed on the grand finale concert of the Minnesota BACH Festival, at Wooddale Church in Eden Prairie. His live performances and recordings have been broadcast many times over National Public Radio on the Pipedreams® program of organ music, as well as on other programs.
In 1997 he founded the Minnesota Chapter of the Organ Historical Society, and served for two terms as its first president. He has performed numerous times at Chapter events.
Ferguson's completion of Bach's Contrapunctus XIV has been performed in London at Westminster Abbey (1995, Mark Brafield), and Westminster Cathedral (1996 Grand Organ Festival, Martin Baker). It has also been performed at Grace Cathedral, San Francisco (2005, Michael Ferguson), Notre Dame Cathedral in Paris (2011, Mark Brafield), and St. Agnes Cathedral, Rockville Centre, NY (2014, Martin Baker); and was recently featured along with Ferguson's Ricercar upon Three Ancient Chorales in recitals of the 2017 national convention of the Organ Historical Society, held in Minnesota (Contrapunctus XIV: Aaron David Miller, House of Hope Presbyterian; Ricercar: Bill Chouinard, St. Andrew's Lutheran).