The great art song recitalist Elisabeth Schwarzkopf often said that she sang primarily for herself, allowing her to pursue the interpretation of her dreams. British tenor Ian Bostridge seemed to take a similar philosophy to a self-indulgent maximum at his Wednesday Brahms/Schumann program at the Kimmel Center, with an idiosyncratic, private manner that one might normally witness while watching someone through a keyhole in a practice room.
Many in the Philadelphia Chamber Music Society's sophisticated audience called him back for three encores. Others wondered if he was of sound mind and body as he worked his way through a program of lesser-known creations of these well-known composers - including Schumann's Liederkreis Op. 24 and songs the composer dropped from the final version of his great Dichterliebe - bobbing, weaving, and at one point seeming to charge off stage in mid-song, suggesting a restlessly Byronic cabaret singer.


