Singing is the act of creating musical sounds with the voice. A person whose profession is singing is called a singer, artist or vocalist. Singers perform music that can be sung with or without accompaniment by musical instruments. Singing is often done in an ensemble of musicians, such as a choir. Singers may perform as soloists or accompanied by anything from a single instrument up to a symphony orchestra or big band. Different singing styles include art music such as opera and Chinese opera, Indian music, Greek music, Japanese music, and religious music styles such as gospel, traditional music styles, world music, jazz, blues, ghazal, and popular music styles such as pop, rock, and electronic dance music.