"Rhythms of the World," this year's Arlington High School Pops concert, will fill Town Hall with the sound of music . . .

Performers of musicals are usually singing actors and opera performers acting singers. . . .

The Boston Ballet production of Swan Lake, with choreography adapted by Mikko Nissinen after Petipa and Ivanov . . .

Opening night of the Boston Ballet Nutcracker, with its spectacular sets and costumes by Robert Perdziola, kicks off . . .