What big composers wrote music for the Alto Saxophone when it was first invented?
The first Saxophone was made around the 1840s and the Alto Saxophone was probably a version of it made a little later. Bizet may have been the very first composer to use it, like for example in his music for L’Arlesienne. Mussorgsky’s Pictures at an Exhibition, has saxophone solo as well, but the orchestration was in fact made by a much later composer, Ravel, when the Saxophone was a little more common (Ravel used it in his own compositions). There are a few Saxophone Concertos, notably the ones made by Glazunov, Ibert, and some similar things by Debussy, that are more in a Classical or 20th Century sense than what saxophone became more popular for in Jazz. Milhaud’s Scaramouche is also a famous little suite for the instrument. Over the whole 20th Century into the 21st, there have been many more composers using this fascinating instrument, but the names before were some of the very first.
