The tenor is used in classical music. It is a standard instrument in concert bands and saxophone quartets. It also has a body of solo repertoire. The tenor is sometimes used as a member of the orchestra in pieces such as Sergei Prokofiev's "Romeo and Juliet" and "Lieutenant Kijé Suite" and Maurice Ravel's "Boléro". Charles Ives employs a tenor in his Fourth Symphony. Vincent d'Indy wrote for a tenor in his opera "Fervaal". Lukas Foss includes a tenor in his Symphony No. 2. The Tenor Saxophone Index, an online repertoire database, was launched in July 2012.