Single

A Single is a music release centered on one primary recording. It is usually named after the lead track and may be issued before or independently of an album for broadcast, promotion, and commercial sale. “Single” can refer to the release itself or, in everyday speech, to the lead song; the two meanings must be distinguished by context.

In the physical-record era, singles were often issued on 7-inch 45 rpm discs, with the lead track on the A-side and another song or alternate version on the B-side. 12-inch maxi-singles, CD singles, and cassette singles can hold more remixes, instrumental versions, live versions, and video content, so a single has never necessarily meant “one track.” What they share is programming organized around a limited lead recording rather than a full album-scale track list. Digital stores and charts classify a release as single or album by track count, total duration, pricing, or product settings, but platform rules are not uniform. Releasing one song alone usually constitutes a digital single, while several independent new songs may be formally defined by the artist as an EP; file count alone cannot determine type in every situation.

The same lead track may first appear as a single and later be included on an album. The two releases may share the same recording and ISRC or use different edits, mixes, or masters; single artwork, catalog numbers, barcodes, and bonus tracks belong to the specific single release. Terms such as lead single, promotional single, and double A-side describe promotional order or track relationships; they do not create new media formats.

Single and Promo are different dimensions. A commercial retail single can be an official public release, while a promotional single may be supplied only to radio, media, or industry personnel; both center on the lead recording but differ in distribution status.