A Solo means music performed by a single musician, for example a pianist alone. In fact piano solos must be the most widely known form of solo music. The word solo is Italian meaning alone. The correct Italian plural should be soli, but in English-speaking musical circles it is perfectly acceptable to say solos.

For a singer to sing a solo, he or she must have a very well-developed sense of pitch and rhythm in order to perform without the support of a piano or other instruments. Other instruments for which many composers have written solos include the flute (Debussy), the harp, the harpsichord, the organ, the guitar, and the violin.