Rainbros leaned into Monseur's arrangement’s intimacy. With the smaller ensemble's vocal blend at the front and a delicate piano accompaniment underneath, the texture stayed transparent throughout, allowing each phrase of Taupin's lyric to register clearly.

Rainbros approached "Mamma Mia" with the snap and intimacy of a small vocal group that knows each other well. The opening marimba-style figure was passed between voices in tight imitation; the verses were traded with theatrical timing; and the choruses bloomed into the kind of close-stacked harmony that small ensembles do better than anyone.