A full score is a score that contains the entirety of a work, inclusive of the parts for all the instruments used in performing it and the libretto, if any. Many scores, especially for longer, more complex works, are abridged versions or contain the part for just one or a group of instruments, such as a piano or the violins. Full scores are used mainly by conductors and others who want to study works in great detail, and to a lesser extent by musicians who specialize in playing a particular instrument.