ABA denotes a ternary (three-part) song form. The first part (A) is followed by a middle part (B) and finally again the first part (A). Possible variants are AAB (the medieval bar form from which the reprise bar form AABA developed) and ABC.

An example of ABA is „Twinkle twinkle little star“. In instrumental music, e.g. the minuet was built in the ABA form. The blues12 has the AAB form, modern pop songs often AABA.