Organist performs at St. Patrick's Cathedral, 5th Ave. (betw. 50th & 51st Sts.), 212-753-2261; 1:30, free.
Manhattan Chamber Orchestra
Richard Auldon Clark conducts Weill's Mahagonny & Berlin Requiem feat. male vocal quartet Songfellows; Trinity Church, 74 Trinity Pl., Wall St. (B'way), 212-602-0873; 2, $2 contrib.
Mannes Bach Institute
Mannes College of Music faculty perform works by Bach feat. oboist John Ferrillo & violinist Lewis Kaplan; Church of the Holy Trinity, 316 E. 88th St. (betw. 1st & 2nd Aves.), 212-289-4100; 8, $15.
George Rothman conducts works by Constant, Debussy & Ravel feat. violinist Olivier Charlier; Alice Tully Hall, 1941 B'way (65th St.), 212-721-6500; 8, $25-$40.
Special Music School of America Chorus
Sean Hartley conducts works by Loesser, Berger, Gilbert & Sullivan; Merkin Concert Hall, 129 W. 67th St. (betw. B'way & Amsterdam Ave.), 212-501-3330; 2, free.
Elvis Costello, Brodsky Quartet
Ensemble performs world premiere of keyboardist Steve Nieve's opera Welcome to the Voice; Town Hall, 123 W. 43rd St. (betw. 6th & 7th Aves.), 212-840-2824; 8, $40-$65.
Hinds Sisters Trio
Ensemble performs works from Purcell to spirituals; Alice Tully Hall, 1941 B'way (65th St.), 212-721-6500; 3, $25-$50.
Holy Apostles Community Chorus
Ensemble performs works by Beethoven, Bernstein, Berlin & Lloyd-Webber; Holy Apostles Church, 28th St. (9th Ave.), 212-475-2702; 4, $5 contrib.
Peter Tiboris conducts American premiere of Mikis Theodorakis' opera Electra; Carnegie Hall, 881 7th Ave. (57th St.), 212-247-7800; 2, $50-$100.
Tribute to jazz composers feat. Lisle Atkinson; Merkin Concert Hall, 129 W. 67th St. (betw. B'way & Amsterdam Ave.), 212-501-3330; 8, $20.
Pianist-composer premieres his Ode for Soprano & String Quartet; Middle Collegiate Church, 50 E. 7th St. (2nd Ave.), 212-877-3399; 7:30, $15, $10 st./s.c.
Mannes College of Music
Faculty perform chamber works by Bach feat. violist Victoria Chiang, pianist Seymour Lipkin & harpsichordist Arthur Haas; Mannes College of Music, 150 W. 85th St. (betw. Columbus & Amsterdam Aves.), 212-580-0210; 8, $15.
West Park Presbyterian Church's "Sing Out"
Fourth annual event to benefit West Park Endowment feat. cabaret legends Carol Hall, KT Sullivan & Celeste Holm; West Park Presbyterian Church, 165 W. 86th St. (Amsterdam Ave.), 212-874-0554; 7:30, $20.