Sackbut as ballet "Don Juan" (1761). Some chamber music in this period includes trombone in an obligato role with voice, and also as a concerto instrument with string orchestra. Composers include the likes of Leopold Mozart, Georg Christoph Wagenseil, Johann Albrechtsberger, Michael Haydn and Johann Ernst Eberlin. For works for trombone post-1800, please see trombone. Many groups specializing in period music make frequent and prominent use of the sackbut. External links: Plenty of recordings of the authentic sackbut are now available from the groups such as Concerto Palatino, HMSC, Gabrieli Consort and the Toulouse Sacqueboutiers. For a closer examination of the
Musical instrument which produce sound by electronic means. Within each category are many subgroups. The system has been criticised and revised over the years, but remains widely used by ethnomusicologists and organologists. Andre Schaeffner, a curator at the Musée de l'Homme, disagreed with the Hornbostel-Sachs system and developed his own system in 1932. Schaeffner believed that the pure physics of a musical instrument, rather than its specific construction or playing method, should always determine its classification. (Hornbostel-Sachs, for example, divide aerophones on the basis of sound production, but membranophones on the basis of the shape of the instrument). His system divided instruments