OVERHEARD ON THE 1 TRAIN: a conversation between two young classicists (Juilliard? Mannes? Manhattan?) about baroque composers. The guy, with what looked like a horn case on his back, was telling his female companion how he fell in love with Bach’s St. Matthew Passion. She asked if he had ever played original instruments—the sort used at the time the music was written. You bet: Just as basketball players don’t play only basketball, he explained, it’s good for us to take a break from modern instruments: “It’s like cross-training for musicians.”