Queen + Adam Lambert is a collaboration between the active members of the British band Queen (Brian May and Roger Taylor) and American vocalist Adam Lambert. As with all other Queen performances since 1997, longstanding bassist John Deacon has declined to participate in the project due to his retirement. This is the first long-term collaboration of Queen since the Queen + Paul Rodgers project ended in 2009. Like the previous project, it was made clear that Lambert would not be replacing Queen frontman Freddie Mercury, but rather that he would be featured with the band's active members.