Singer Adam Lambert will join British rock band Queen in July for one performance, and guitarist Brian May says Freddie Mercury would approve.

The 30-year-old Lambert will join Queen at the Sonisphere Festival in Knebworth, England on July 7.

The iconic rock band currently includes May and drummer Roger Taylor. Taylor and May formed the band Smile, which frontman Mercury altered to Queen when he joined. Mercury died in 1991 of complications due to AIDS.

“Judging by my incoming mail, this decision will make a lot of people very happy,” May said in making the announcement on the band's official website. “It's a worthy challenge for us, and I'm sure Adam would meet with Freddie's approval!”

Lambert first discussed joining Queen at the Sonisphere Festival in England in comments made to the UK's Daily Star.

“The intention is to pay tribute to Freddie [Mercury] and the band by singing some fucking great songs,” he said. “It's to keep the music alive for the fans and give it an energy that Freddie would have been proud of.”

“I haven't confirmed any guest appearances,” Lambert tweeted earlier this month. “I was talking about the EMAs”

Lambert performed several songs with Queen at last year's MTV European Music Awards (EMA) in Belfast.