Ain’t ain’t a word

Ain't No Rest for the Wicked - Cage The Elephant

Ain’t nobody, Chaka Khan

Just an uttered sound that effectively conveys ones feeling.  Same as a grunt used in a reply.

Aint livin long like this- Waylon Jennings

Ain't That A Shame:  Fats Domino

Ain't No Big Thing:  Radiants

Ain't No Mountain High Enough:  Marvin & Tammi

Ain't Too Proud To Beg:  Temptations

Ain't No Woman (Like The One I Got):  Four Tops

Ain't Even Done With The Night:  John Mellencamp