Couillaud's Melodic Music for Trombone, or “Pièces Mélodiques”, is a very interesting collection. You will see in the top of the first two books that it was originally titled 24 Melodic Studies, because each book has 12 pieces and there were only two originally published. Eventually Couillaud wrote a third book and the entire set because 36 Melodic Pieces for Trombone.
This three volume set includes original music for trombone, as well as vocalises by Dukas, Gaubert, Lefebre, Paray, Busser, and other French composers. The melodies are in a French impressionist style and include many legato flourishes and modal writing characteristic of French vocal lines.
These are very approachable and very satisfying to play. Please grab your horn and try out 3 pages of free samples, then grab the entire set above.
All of these books by Couillaud have only be available in oversized European editions until now. These books are priced at 50% of retail in the hopes that they will be adopted by a growing number of players worldwide.