The Conservatoire was not the only institution concerned about how to use valved instruments effectively in art music. In an effort to improve military music, the Conservatoire absorbed the training of military musicians early on, but there were still periods where improvements were slow to develop. The result was the establishment of a separate Gymnase de musique militaire in 1836, with its own collection of teachers. These teachers also wrote their own method books, and the two who wrote for the horn include Georges Kastner (1840), who later wrote a comprehensive history of military music up to that point that included important developments in valve technology, and Donatien Urbin, former student at the Conservatoire, and proponent of the use of three valves on the instrument (as opposed to Meifred’s preference for just two). This chapter includes a summary of the formation of the Gymnase and a close look at the horn methods by Kastner and Urbin for comparison with that of Meifred. There was both common ground and differing opinions on how the technology was best used. Since training of military musicians had been absorbed by the Conservatoire, at least for short periods of time, a discussion of the Gymnase is relevant at this juncture.