On Saturday, Elton John performed at the wedding of Rush Limbaugh, a rightwing DJ who has previously denied the severity of AIDS in Africa. The British singer, a leading AIDS activist, reportedly received $1m (£690,000) for the appearance.

Limbaugh, 59, married Kathryn Rogers, 33, at a ceremony in Florida's Palm Beach. The guests of the controversial American radio host included former Republican svengali Karl Rove, former New York City mayor Rudolph Giuliani and Fox News talk-show host Sean Hannity, according to People magazine. Sir Elton serenaded 400 guests into the wee hours, with security on hand.

Even more unexpectedly, Sir Elton's million-dollar fee may have been a reduced rate. Last year, Reuters reported that the Candle In the Wind singer is the "second most expensive" wedding performer, charging more than $2m (£1.38m) for private gigs. Proceeds from these concerts go to the Elton John AIDS Foundation.

Reduced rate or not, performing at Limbaugh's wedding is an odd choice for the gay rights and AIDS activist. Limbaugh is one of the most maligned figures in American politics, loathed by the left, and has been accused of being both a homophobe and an AIDS denier. Last October, Limbaugh compared H1N1 to AIDS in Africa, a "hyped" disease. "Everything in Africa's called AIDS," he said on his radio show. "The reason is [that] they get aid money for it. AIDS is the biggest pile of – the biggest pot they throw money into."

The shock jock provoked similar outrage in 2007, when he claimed AIDS had not yet "spread to the heterosexual community". "There was never any evidence that it was spreading [there], not sexually anyway, and if you said that, then you were guilty of a hate crime," he said. "It was time to cough up money for education, and condoms, and cucumbers and all that, and we had rock stars like Bono establish philanthropic careers on the basis of all this, all based on 'science.'"

Although Limbaugh has historically supported civil partnerships, he has shown little restraint with jokes about gay people, using homophobic taunts to criticise his political opponents. "When a gay person turns his back on you, it is anything but an insult; it's an invitation," he once said.