The star pianist Yefim Bronfman performs in New York often, but I have never seen him. That was rectified last night: I caught him in the first of three concerts with the New York Philharmonic at Avery Fisher Hall. He was remarkable. Performing Brahms Piano Concerto No. 2, he captured the full range of emotions in the piece--its subtle bits of humor, the breezy wistfulness, the heroic ambition--without drawing much attention to himself.