Bart regularly works as a guest conductor, and has done a number of recordings of lesser-known compositions by a range of artists from Fétis and Lemmens to cutting edge composers like the American Elliott Carter. As assistant conductor he has also led La Chapelle Royale, the Vlaams Radio Koor, the Collegium Vocale, Il Gardellino and the Amsterdam Baroque Choir. In 2008 he was appointed artistic director of the Al Ayre Español choir.
He is also the artistic director of the La Hispanoflamenca ensemble, who specialise in the 16th and 17th Century polyphony of the Netherlands and the Iberian Peninsula. Gustav Leonhardt, Monica Huggett and Enrico Onofri have all been guest conductors with La Hispanoflamenca.