Reviewed by Lee Shepherd I couldn’t shake the image of that PBS commercial. You know the one I mean. The camera zeroes in on a piano quintet. The music builds to a fever pitch. The musicians flail in their seats, tossing their hair wildly. Piano strings pop, violin strings break, bow hairs come loose and the climax? The string players smash their instruments. The message: “Be more passionate.” That’s how the Brentano String Quartet plays – with such passion and ferocity that their instruments almost burst into flames.