A concert, often known informally as a gig or show, is a live performance of music in front of an audience. The performance may be carried by a single musician, in which case it is sometimes called a recital, or by a musical ensemble such as an orchestra, choir, or band. Concerts are held in a wide variety of settings and sizes, spanning from venues such as private houses and small nightclubs to mid-sized concert halls and finally to large arenas and stadiums, as well as outdoor venues such as amphitheatres and parks. Indoor concerts held in the largest venues are sometimes called arena concerts or amphitheatre concerts.