A laureate conductor of the Yehudi Menuhin Foundation, McDonnell began his musical studies with the violin at the age of 8. At 19 years old he was selected by competition for the position of apprentice conductor for the State of North Carolina, where he studied conducting with Sheldon Morgenstern and Peter Paul Fuchs, then with Richard Pittman at the New England Conservatory in Boston and with Pierre Dervaux in France.
He has held permanent positions as a conductor with the Greensboro Symphony Orchestra, Greensboro Opera, Eastern Music Festival, Guilford Symphony Orchestra, Orchestre inter-conservatoires de la Ville de Paris, and has conducted numerous symphony orchestras in Europe and the United States as a guest conductor.