Pieces intended for solo voices and orchestra (either with or without a minimum chorus) can be found in a variety of genres. The most common context for this kind of ensemble is opera or musical theater, where one or more singers perform alongside an orchestra (usually in an accompaniment role). Standalone pieces originally written for voice an orchestra can also be found, such as the so called 'orchestral songs'. Orchestral songs tend to be longer than piano pieces, and often display programmed content.