Carl Philipp Emanuel Bach's Sonatas with Varied Reprises (completed 1758-9, published 1760) constituted a bold experiment. Spelling out every repeat, Bach applies to each the art of variation. Starting off as a service ("play this and you'll sound as if you're improvising"), the opus ends up a masterclass in variation. Tom Beghin, playing his own beloved clavichord, enacts the role of the keyboardist-composer who repeats himself, while never saying the same thing twice.

Tom Beghin has been at the forefront of a new generation of interpreters of 18th- and early 19th-century music.

His discography features Beethoven, Mozart, Haydn, Moscheles, C.P.E. Bach, Mendelssohn, Zelter, Schubert, and Clementi. He has published in journals such as Keyboard Perspectives, 19th Century Music and Haydn Studien, and in collections such as Haydn and His World, The Cambridge Companion to Haydn, and The Oxford Handbook of Topic Theory. With classicist Sander Goldberg he edited Haydn and the Performance of Rhetoric, winner of the 2009 Ruth Solie Award from the American Musicological Society. In 2015 The University of Chicago Press published his monograph The Virtual Haydn: Paradox of a Twenty-First Century Keyboardist.

Recognised for his expertise in eighteenth-century music, he is frequently invited to give concerts, workshops and lectures throughout North America and Europe. In 2013 he inaugurated the first replica of Beethoven's 1817 Broadwood piano at the Concertgebouw in Bruges and the Beethoven- Haus in Bonn, playing among others Beethoven's "Hammerklavier" Sonata, op.106.