[5][6] Also in 1987, Michael collaborated with Aretha Franklin on the UK and US number one single "I Knew You Were Waiting (For Me)".

In November 1991, Michael released "Don't Let the Sun Go Down on Me", a duet with Elton John; it reached number one in the UK and US.

[3][7] In 1993, Michael released his version of "Somebody to Love", which was performed at the Freddie Mercury Tribute Concert with Queen.

[3] Twenty Five, released in 2006, was Michael's second greatest hits album, celebrating the 25th anniversary of his music career.

[3] The album contains songs mainly from Michael's solo career and two new songs: "An Easier Affair" and "This Is Not Real Love" (a duet with Mutya Buena, then a member of the Sugababes, and now a member of Mutya Keisha Siobhan).

[8] The following year, "December Song (I Dreamed of Christmas)" was officially released as a commercial single.