This category covers works written for between two and ten instruments. The most popular chamber music works are sonatas for piano and one other instrument such as violin or cello and string quartets. Most great composers have written such instrumental sonatas and quartets. Other chamber music formats are the trio (three instruments—for example, piano trios feature piano, violin and cello), the quintet (five instruments, frequently five string instruments—Schubert’s Trout Quintet for piano and four string instruments is perhaps the most famous chamber music work of all time), the sextet (six instruments), the septet (seven instruments), the octet (eight instruments) and the nonet (nine instruments). There are also a few works for ten instruments known by the French name dixtuor.