 Piano–vocal scores are also used by music students, singers and conductors to study the compositional structure of the score.Before the widespread availability of sound recordings, piano–vocal scores were also sold for amateur home performance or small-scale professional performance of the piece, where a full orchestra would not be feasible from an economic or performance space perspective.While piano-vocal scores tend to consist of the vocal lines and a piano reduction of the whole orchestra onto two staves, piano-conductor scores tend to consist of the vocal lines and one of the orchestral piano parts that already exists, coupled with another staff containing the rest of the orchestral reduction (in contrast to a piano-vocal score, where the piano and other orchestral parts cannot be easily separated at sight).