Mama is a pop ballad, written in the key of F minor, it is set in the time signature of common time and moves at a moderate tempo of 100 beats per minute. The song is constructed in a verse-chorus form, with a with a bridge before the third chorus, and its instrumentation comes from keyboards, a rhythm guitar, a cello, and a violin.
It opens with an instrumental introduction, with a chord progression of D♭–E♭–Fm–E♭/G–A♭, that is used in the entire song. Bunton and Brown sings the first and second verse respectively. The bridge and third chorus follows. Then a choir arranged by Mark Beswick, supplemented the group during the last part of the song, which consists in the repeatition of the chorus until it gradually fades out.