Kicking off his mini-tour, Adam Lambert teamed up with Queen on a special rendition of the group's famous song "Bohemian Rhapsody" on Saturday.
Taking place in Kiev, Ukraine, they performed a 2-hour set as part of a joint concert with Elton John to benefit AIDS research.
Twitter users have sounded off about the pair's 2-hour set, praising Lambert for his contribution to the iconic group.
"Adam Lambert plus Queen equals something too beautiful for words," wrote Kylie.
Nicole posted, "I definitely have respect for Adam Lambert."
Their set included well-known Queen songs such as "We Will Rock You," "Fat Bottomed GIrls," and "Another One Bites the Dust," among many others.
During the concert, John told fans to stand against violence against homosexuals in Ukraine and shed light on May incident where organizers of a planned gay pride march were beaten.
Lambert first performed with Queen as a contestant on "American Idol" and joined them during performances at the 2011MTV European Music Awards. The artists planned on performing at the U.K. Sonisphere Festival ahead of the event's cancellation in March.
Despite the cancellation, the 30-year-old "American Idol" alum will serve as frontman for Queen during several upcoming shows this year. Their next stop is Russia for a July 3rd concert at the Olympic Arena in Moscow.
Lambert recently released his new album "Trespassing" in the U.S. and has sold 77,000 copies during its first week. Speaking about the album's success, Lambert told DigitalSpy.com that "pleased is an understatement."
"I'm so relieved that people liked it," said the singer. "As I worked so hard on the record."
Lambert has become the first openly gay male artist to score the top position on Billboard's album chart with "Trespassing." The album is available to hear online for free, which he believes will increase his popularity.
"I think putting the album up online was a handy tool for a lot of people," he said. "As there are still a lot of preconceived ideas about what I'm about. One of the great things about 'Trespassing' is that I think it really carves out my sound and vibe."
To listen to "Trespassing," visit AdamOfficial.com.