In 1824, Schott in Mainz published a trumpet method by C. EugŠne Roy. A facsimile reprint of it has been published in 2010 as volume 1 of the HKB- [Bern University of the Arts] Historic Brass Series. The original includes these duets in an antiquated mixed pitch configuration: the first voice for a high E flat trumpet, the second being in Bb. These have been transposed here for modern instruments in either C or Bb. --the publisher