A面与B面（英语：A-side和B-side），这名称产于1950年代，原本指出版的7英吋黑胶唱片（必须是单曲）的两面。现在A面和B面通常用来辨别歌曲的重要度——放在A面的歌曲属于主打歌（歌手会期望这些歌会经常在电台播放）；放在B面的歌曲属于次要歌。

A-Side和B-Side最初是指7寸黑胶碟的两面，唱片业从1950年代开始将单曲录制在这种介质的两面。A-Side和B-Side逐渐被用于形容录制在盘片两面的两种不同类型的歌，A-Side通常录制的是我们所说的主打歌（那些被用来打榜或者期望在电台节目里热播的曲目），B-Side（或称flipside）是指的第二类歌，这些歌通常不会出现在乐队的LP（Long playing record album）中。

The terms A-side and B-side refer to the two sides of 78 and 45 rpm phonograph records, whether singles or extended plays (EPs). The A-side usually featured the recording that the artist, record producer, or the record company intended to receive the initial promotional effort and then receive radio airplay, hopefully, to become a "hit" record. The B-side (or "flip-side") is a secondary recording that has a history of its own: some artists, notably Elvis Presley, Little Richard, the Beatles, Chuck Berry, and Oasis, released B-sides that were considered as strong as the A-side and became hits in their own right. Creedence Clearwater Revival had hits, usually unintentionally, with both the B-sides of their A-side releases. Others took the opposite track: producer Phil Spector was in the habit of filling B-sides with on-the-spot instrumentals that no one would confuse with the A-side. With this practice, Spector was assured that airplay was focused on the side he wanted to be the hit side.