"It was less painful giving birth," mutters Sarah, whose husband is in Afghanistan, as Gareth Malone coaxes her to sing a few notes. Sam is almost worse: a lovely voice but she can barely sing a bar without interrupting herself. "Sorry, sorry..." she says, then apologises for apologising.
It's the big surprise for Gareth: the soldiers' wives and girlfriends, who spend months stoically waiting for their menfolk to return from conflict, are in many cases lacking in confidence. "For very good reasons, they've clammed up," Gareth observes, before delivering the sweet balm of choral singing.