Editing Song structure (section)

===Ad lib===
{{Unreferenced section|date=February 2020}} 
An ''[[ad libitum|ad lib]]'' section of a song (usually in the [[Coda (music)|coda]] or [[Conclusion (music)|outro]]) occurs when the main lead vocal or a second lead vocal breaks away from the already established lyric and/or melody to add melodic interest and intensity to the end of the song. Often, the ad lib repeats the previously sung line using variations on phrasing, melodic shape, and/or lyric, but the vocalist may also use entirely new lyrics or a lyric from an earlier section of the song. During an ad lib section, the rhythm may become freer (with the rhythm section following the vocalist), or the rhythm section may stop entirely, giving the vocalist the freedom to use whichever tempo sounds right. During live performances, singers sometimes include ad libs not originally in the song, such as making a reference to the town of the audience or customizing the lyrics to the current events of the era.

There is a distinction between ad lib as a song section and ad lib as a general term. Ad lib as a general term can be applied to any free interpretation of the musical material.