Here are scattered notes on recent concerts, of use to unknown persons. Oct. 20: Christopher Maltman at Zankel Hall. I first encountered this vibrant baritone singing Britten's Fourth Canticle with Ian Bostridge in London. Here he wasn't in best voice — he hit a dry patch in Mahler's Rückert Lieder — but a ringing declamation of "Um Mitternacht" saved the day. If Gerald Finley tires of singing Oppenheimer, Maltman could take over. Oct. 21: Così fan tutte at the Met. In a fine cast, the standout was Mariusz Kwiecien, as Guglielmo. He has liquid legato, superb diction, charm to burn. Terfelesque. Oct. 23: Royal Stockholm Philharmonic at Carnegie. What I liked most about Alan Gilbert's confident handling of the Prokofiev Fifth was that he brought out the quality of instability, the hint of terror, that lurks in the music right at the end. Oct. 25: Caught the first part of the Two Sides Sounding recital at St. Peter's, then the last part of Youssou N'Dour at Zankel. Corey Dargel's Condoleezza Rice song cycle — setting three passages from the Secretary of State's speeches — sounded prankish in concept, but was surprisingly moving in execution; the prosody was immaculate, the accompaniment achieved a certain Handelian grandeur. I recommend these songs to sopranos of daring. More on the joy-bringing Youssou another time.