By Caldwell Titcomb

Ursula Oppens presents a free piano recital at Harvard University.

April 1: Ursula Oppens, long a champion of contemporary music (and a 1965 honors graduate of Harvard), presents a free piano recital under the auspices of the Blodgett Distinguished Artists Series. The program includes John Corigliano’s “Winging It,” William Bolcom’s “Ballade,” Tobias Picker’s “Three Nocturnes,” the world premiere of Charles Wuorinen’s “Oros,” several pieces by the 101-year-old Elliott Carter, and Amy Williams’ Three Pieces for Piano. At Paine Hall, Harvard University, 8 p.m.

April 1-3: Vincenzo Bellini’s rarely performed opera I Capuleti e i Montecchi (1830), based on the Romeo and Juliet story, is staged by the Boston Conservatory Opera Program and performed in Italian with English surtitles. At Midway Studios, 15 Channel Center Street, Boston, 8 p.m. all three days plus a matinee at 2 p.m. on April 3.

April 5: The New England Conservatory’s free “First Monday” series celebrates the 300th anniversary of Pergolesi’s birth with a performance of his “Sinfonia” for two cellos, along with Bartók’s Duos for Violin, transcribed for violas, Gyorgy Kurtág’s “Signs, Games and Messages,” and Schubert’s celebrated “Trout Quintet.” At Jordan Hall, 30 Gainsborough Street, Boston, 8 p.m.

April 6: The Boston Conservatory’s Piano Masters Series presents prize-winning Ya-Fei Chuang, who will play four of Mendelssohn’s “Songs Without Words,” all four of Chopin’s Scherzi, three sonatas by Scarlatti, Yehudi Wyner’s “Towards the Center,” and Ravel’s “La Valse.” At Seully Hall, 4th floor, 8 The Fenway, Boston, 8 p.m.

April 7: Hugh Wolff leads the NEC Philharmonia in Schumann’s Cello Concerto (with Narek Hakhnazaryan as soloist) and Shostakovich’s wonderful Symphony No. 10. At Symphony Hall, 301 Massachusetts Avenue, Boston, 8 p.m.

April 8-10: With conductor James Levine sidelined again for reasons of health, the the Boston Symphony Orchestra still has scheduled the world premiere of John Harbison’s “Double Concerto” for violin and cello, followed by Mahler’s huge and demanding Symphony No. 7. Filling in for Levine will be the globally active Carlos Kalmar, music director of the Oregon Symphony Orchestra. At Symphony Hall, 301 Massachusetts Avenue, Boston, April 8 at 10:30 a.m.(open rehearsal) and 8 p.m., April 9 at 1:30 p.m., April 10 at 8 p.m.

April 9: The Celebrity Series brings the St. Lawrence String Quartet to town for the Boston premiere of the String Quartet by John Adams, widely considered the foremost living American composer. Also on the program are Haydn’s Quartet in E-flat Major, Op. 9, No. 2, and Dvořák’s Quartet No. 13 in G Major, Op. 106. At Jordan Hall, 30 Gainsborough Street, Boston, 8 p.m.

April 10: The Triple Helix Piano Trio ends its season with a free all-American program: William Bolcom’s “Violin Sonata No. 2,” Aaron Copland’s “Twelve Poems of Emily Dickinson” (with soprano Sarah Pelletier), Charles Ives’s “Piano Trio,” and a world premiere by Cambridge composer Howard Frazin. Houghton Chapel & Multifaith Center, Wellesley College campus, 106 Central Street, Wellesley, 8 p.m.

April 16: Today’s most exciting conductor, Gustavo Dudamel (now honcho of the Los Angeles Philharmonic at the age of 29), visits MIT and leads the MIT Symphony Orchestra in a free open rehearsal. At Kresge Auditorium, MIT campus, 48 Massachusetts Avenue, Cambridge, 7 p.m.

This year marks the 100th birthday of celebrated American composer Samuel Barber.

April 17: The MIT Chamber Chorus, under the direction of William Cutter, celebrates the 100th birthday of Samuel Barber with a free concert entirely devoted to choral, solo, and operatic music by this major American composer. At Kresge Auditorium, MIT campus, 48 Massachusetts Avenue, Cambridge, 8 p.m.

April 18: The Boston Conservatory Orchestra, led by Bruce Hangen, performs Marquez’s “Danzon No. 2,” Villa-Lobos’ “Bachianas Brasileiras No. 2,” Ginastera’s “Estancia,” and Barber’s Piano Concerto, Op.38, with this year’s concerto competition winner Shih-Weh Cheng as soloist. At Sanders Theatre, Harvard University, 45 Quincy Street, Cambridge, 2 p.m. (Dr. Elizabeth Seitz will talk about these works at 1 p.m.)

April 23-May 4: The Boston Lyric Opera ends the season with Mozart’s rarely staged Idomeneo, K. 366 (1781), with Jason Collins making his company debut in the title role. Lillian Groag is the stage director and David Angus the conductor. Sung in Italian with English surtitles. At the Shubert Theatre, 265 Tremnont Street, Boston, April 23, 28, 30 and May 4 at 7:30 p.m.; April 25 and May 2 at 3 p.m.

April 30: Robert Levin and Ya-Fei Chuang, duo-pianists, will offer the premiere of John Harbison’s “Diamond Watch: Double Play for Two Pianos.” Also on the free program are Stravinsky’s “Sonata for Two Pianos,” Rachmaninoff’s “Suite for Two Pianos No. 2,” Lutoslawski’s “Variations on a Theme of Paganini,” Poulenc’s “Sonata for Two Pianos,” and an arrangement of Harbison’s “David’s Fascinating Rhythm.” At Kresge Auditorium, MIT campus, 48 Massachusetts Avenue, Cambridge, 8 p.m.

April 30: Jameson Marvin, who is retiring after 32 years as director of choral activities at Harvard, conducts the Harvard Glee Club, Radcliffe Choral Society, and Harvard-Radcliffe Collegium Musicum in a cappella repertoire and festive concerti by Heinrich Schütz along with the premiere of a work by Robert Kyr composed in Marvin’s honor. At Sanders Theatre, 45 Quincy Street, Cambridge, 8 p.m.

April 30-May 4: Opera Boston stages a real novelty: Jacques Offenbach’s satirical La Grande-Duchesse de Gérolstein (1867). The production stars mezzo-soprano Stephanie Blythe, with David Kneuss as stage director and Gil Rose as conductor. Sung in French with spoken English dialogue and surtitles. At Cutler Majestic Theatre, 219 Tremont Street, Boston, April 30 and May 4 at 7:30 p.m.; May 2 at 3 p.m.