Classical. Originally thought to be composed for two Horns, the Twelve Duos K. 487 have been transcribed for two Euphoniums by Ralph Sauer, retired Principal Trombonist of the Los Angeles Philharmonic. Mr. Sauer has set them into three sets of keys. 1-4 are in F, 5-8 are in G and 9-12 are in A, giving the performers a nice mix of keys. This also makes three sets of Duos that can be used in recital if desired. The Duos can be performed by moderately advanced players. -the publisher