LOS ANGELES

THE biggest question hovering over Sunday’s Grammy Awards was answered yesterday when it was announced that Amy Winehouse, the troubled British pop star and tabloid fixture, would not be able to attend. Ms. Winehouse, who was expected to be the dominant figure at the 50th annual awards ceremony, has been denied a visa to enter the United States.

Grammy producers said, however, that they planned for Ms. Winehouse, who had recently entered a rehabilitation clinic, to appear, probably via satellite, during the program, which will be televised live from the Staples Center here at 8 p.m. Eastern time on CBS.

“You will see Amy Winehouse on the Grammys,” said Ken Ehrlich, the longtime producer of the show. “I’m very happy.”

Ms. Winehouse’s music and image are a bridge between 1960s girl-group pop and modern-day hip-hop, and her addition to the show’s lineup would fill a stylistic void as Grammy organizers strain to honor 50 years of musical history while staking a claim to post- MySpace relevance. But there may be some awkward moments if Ms. Winehouse, who has six nominations  for her album “Back to Black” (Universal), her self-referential single “Rehab” and herself, as best new artist  is a big winner. Only Kanye West has more nominations.