SOLO, (Ital.) a term used in musical compositions of several parts, to mark those voices or instruments that are to perform alone or in a more prominent manner; as, soprano solo, violin solo, &c. The plural is used when two or more voices or instruments of the same name are to perform alone. Solo is also a name given to a composition written for a single instrument, such as a violin, an oboe, a flute, &c., which is accompanied by a bass for the violoncello, or a thorough-bass for the pianoforte.