In line with the excellent work I have heard at Tanglewood, was the Fellows’ vocal concert. Kurt Weill’s The Seven Deadly Sins was masterfully led by mezzo-soprano Fleur Barron, Nuno Coelho, conductor, with Nicholas Muni as director. Mr. Muni’s direction was not fussy, and it tapped into the knife-edged nature of the show without excess. Ms. Barron gave a masterful performance. Not only was her voice beguiling in every way, she moved decisively, and somehow naturally, through the opera. Each of her skills contributed to a larger convincing performance in this ice-cold piece.