NEW YORK — “Saturday Night Live” was built with a cast of young no-names performing countercultural comedy. Fifty years later, it is firmly part of the culture, dictating mainstream comedy instead of throwing spitballs from the margins.

The Homecoming Concert, with iconic stars and musical performances live from New York’s Radio City Music Hall, hosted by Jimmy Fallon and streaming on Peacock. It leads up to Sunday, when a star-studded lineup of Saturday Night Live cast members past and present will participate in the anticipated SNL50: The Anniversary Special.

Live has delivered a regular dose of New York City to millions of TV viewers for a half-century. Now, the city – or at least Midtown Manhattan – is getting a heavy dose of SNL. Downstairs from the NBC staple’s home at 30 Rock’s Studio 8-H,