From the BSO website:
All-Beethoven Program – Canceled
Due to security concerns resulting from the unfortunate events that occurred at the Boston Marathon today, tonight’s Boston Symphony Orchestra concert has been canceled. Ticket holders will be contacted within the next 24-48 hours, with further details on when the concert may be rescheduled. We apologize for the inconvenience and appreciate your patience and ongoing patronage.
Local resident Gabriela Montero who missed out on her Emperor Concerto messaged: My concert is cancelled tonight due to the explosions in Boston. My heart goes out to the victims….