- April 5, 1931 – Easter Sunday. The Russian bells of Lowell House ring out for the first time in Cambridge.
- April 23, 1955 – The Harvard Glee Club and the Radcliffe Choral Society perform Bach’s B-minor Mass with the Boston Symphony Orchestra under Charles Munch. The concert marks the 100th collaboration of the BSO, the Glee Club, and the Choral Society. In a quiet postconcert ceremony, Munch receives the second Harvard Glee Club Medal for “outstanding contributions in the field of choral music.”
- April 28, 1956 – The Harvard Observatory’s radio telescope at Agassiz Station (Harvard, Mass.) is dedicated. President Nathan Marsh Pusey delivers remarks for the occasion. The six-story-high instrument boasts a 60-foot paraboloid antenna that is the largest yet built in the U.S. Construction was financed by a $135,000 National Science Foundation grant and by an anonymous donor.
- April 1957 – To the delight of Boston Red Sox fans, the Harvard Band performs on opening day at Fenway Park.
– From the Harvard Historical Calendar, a database compiled by Marvin Hightower