“Spine-tingling, soul-stirring concert-hall experiences haven’t exactly been thick on the ground at this festival. So to hear massed Scottish forces hurling out James MacMillan’s sensational Quickening under Garry Walker’s cool-headed direction was thrilling…. Using a richly allusive libretto by Michael Symmons Roberts, it deals with the concept of birth in all its explosive, miraculous, life-changing and occasionally threatening forms.”