LOS ANGELES: The music industry's top night turned into the big day for 34 couples on Sunday as Madonna and other stars presided over a mass wedding in a celebration of gay marriage.

The 34 couples -- some same-sex, some opposite-sex and diverse in race and appearance -- exchanged rings before the Grammys stage at Los Angeles' Staples Center, which was momentarily transformed into a brightly lit church with a gospel choir.

The couples' wedding serenade was “Same Love,” performed by hip-hop duo Macklemore & Ryan Lewis.

The Grammy-nominated song has been embraced by marriage equality campaigners as momentum builds in a growing number of countries and US states to allow same-sex partners to tie the knot.

Macklemore and Lewis, who racked up Grammys including best new artist, were joined halfway through their song by one of the gay community's most enduring icons -- Madonna.

Sporting a white suit and cowboy hat, Madonna sang the high-energy chorus of her 1986 song “Open Your Heart.”

The marriages were made official by Queen Latifah, who is authorized to perform weddings in California.

“When we say music has the power to bring people together at the Grammys, we mean it,” a visibly moved Queen Latifah told the audience.

“Tonight, we celebrate the commitment to love by all of these beautiful couples,” she said.

“We are gathered together here to celebrate love and harmony in every key and every color.

”The New York Times, which reported on the mass wedding shortly before the ceremony, said that the Grammys' producer, Ken Ehrlich, approached Macklemore and Lewis about the idea after learning that the duo's concerts have generated on-stage marriage proposals.

A casting agency recruited couples, initially telling them only that the wedding would take place on live television and insisting that they sign confidentiality agreements so that they would not even tell their families, the newspaper said.

Ehrlich was quoted as saying that the couples stayed in aisles near the audience out of concern it would be seen as “exploitive” if they went on stage.

US awards ceremonies have increasingly embraced gay rights in recent years, with the Oscars stereotypically viewed as a top television event for the gay community.

In 2001, rap superstar Eminem, under fire for his use of anti-gay epithets, performed a duet at the Grammys with the openly gay Elton John.

Seventeen US states and the capital Washington allow gay marriage, and opinion polls show that a majority of Americans support same-sex couples' right to wed, a rapid turnaround in just the past decade. Same-sex marriage is legal in all or part of 16 other countries.