Norwood Stage described it as a "comic song".[3] Wicked Local North of Boston said it was a "cute comical song and dance".[4] Independent Newspapers said it "provide[s] comic relief".[4] AussieTheatre called it a "comedy number".[5]
The Real Chrisparkle commented: "When Bad Wolf and I were talking about the show beforehand, we both agreed that “Sing” is probably our least favourite number, because of its potential to irritate; just slightly. But it occurred to me whilst watching it, that it must be extraordinarily demanding for its performers. You need the verbal dexterity of a Gilbert and Sullivan patter song, coupled with immaculate comedy timing and, from Kristine, the ability to sing credibly off-key."[6] StageWhispers named it a "funny, rapid-fire duet".[7] The Rider News noted "“Sing!” makes for a great contrast in the play, breaking the tension and adding in quirky humor".[8]