A "solo" or "single" refers to a musical piece performed by one artist or musician without accompaniment. This format allows the performer to showcase their individual talent and style, often highlighting their vocal or instrumental skills. Solos can be found in various genres, including classical, jazz, and pop. In the context of music releases, a "single" is a song released separately from an album. Singles are often used to promote an upcoming album or to highlight a particular track. They can also be released as standalone pieces, allowing artists to reach audiences quickly and effectively.