As recitalist, Mr. Appel has performed at Carnegie and Avery Fisher Halls in New York, as well as halls from the Music Academy of the West to the Smithsonian in Washington DC. Besides his work with the Four Nations Ensemble, he is a member of the Smithsonian Players, Orpheus, The Violins of Lafayette, and several European chamber orchestras as continuo. He has enjoyed critical acclaim for his previous recording of Bach works where he plays and records for ASV/Gaudeamus with Four Nations Ensemble. Appel's edition of the complete works of Gaspard Le Roux will be published by L'Oiseau Lyre, Monaco.

As a writer, Mr Appel has written programme notes and articles for presenters around the USA including Lincoln Center and National Public Radio. Mr Appel has participated in discussions on education and chamber music programming at conferences of Chamber Music America, the Association of Performing Arts Presenters, and the New York State Council on the Arts. Most recently, he has been asked to serve as Trustee of Chamber Music America. First prize winner of the Erwin Bodkey Competition in Boston, he holds an international soloist degree from the Royal Conservatory in Antwerp and a Doctorate from the Juilliard School where he has taught harpsichord and music history.