Take the ubiquitous crosstown bus and cellphone combination and inexplicably add an opera singer and you’ve got the latest Metropolitan Diary:

My daughter, a social worker at Bellevue Hospital Center, was returning to her apartment on the crosstown bus after work. It was crowded and noisy — a situation not helped by one woman’s loud cellphone conversation.

In exasperation, one passenger began singing opera in an effort to drown her out. This did not help matters. The chatterer, whose volume rose steadily as she competed with “La Bohème,” explained to her cellphone buddy: “It’s a little hard for me to hear you; someone on my bus is singing.”