An eccentric pop star and an aging crooner — why not! In 2014, they sang together on an album of jazz standards, including the song "Cheek to Cheek." Listeners who thought that Lady Gaga's talent was restricted to producing electropop hits à la "Poker Face" discovered that she was a versatile singer.

Without any previous announcement or marketing, and exclusively for streaming, the power couple released a surprise collaborative album, Everything is Love. While the ups and downs of Jay-Z's and Beyoncé's marriage were publicly revealed through previous solo albums, the fact that the Carters ended up doing a joint work is perhaps not as surprising as these other legendary duos...

An opera diva alongside one of the most dazzling personalities in rock and pop history. Freddie Mercury's characteristic vocals met classical soprano. The song "Barcelona" was recorded in 1987. Mercury was fascinated by the Caballé at that time and the two became close friends. They performed the song twice on stage.

The pope of gothic rock and a singing disco ball: How is that supposed to work together? If the duet "Where the Wild Roses Grow" is any indication, amazingly well. Morbid, beautiful, lyrical, the song tells the story of a man who murders his lover. Kylie makes an appearance in the video as one of the most exquisite water corpses in pop music history.

A powerful voice meets a rock'n'roll legend: In 2008, director Martin Scorsese brought Aguilera and the Stones together for the concert film Shine a Light. The song "Live With Me" is an explosive duet in which Mick Jagger and the pop diva give it all they've got. Stones guitarist Keith Richards claimed that he didn't recognize the lady on stage but after that hit, that should have been rectified.

Alt-rocker Udo Lindenberg took to the stage for his live album, titled MTV Unplugged - Live from the Hotel Atlantic, and brought this pop prodigy along with him. The already-successful songwriter Clueso joined Lindenberg for a joint interpretation of Lindenberg's song "Cello.2 It is one of the most beautiful recordings on the album.

In "Sweet Summer Wine," a mysterious beauty, performed by Nancy, beguiles the rich stranger with a bowl of strawberries, cherries and alcohol. Lee Hazlewood had initially intended the song as a B-side. But after it went off the charts, they produced an entire album in collaboration, titled Nancy & Lee.

"Something Stupid" is a love song that gets under your skin. It sounds weird, as it's sung by father and daughter, but the duet became one of the most famous of all time. Maybe it was so good because the two of them did not take the song seriously, but kept making faxes during the recordings, a move that made the sound engineers pale.

A one-hit wonder collaboration that was worthwhile for both of them: "Don't Go Breaking My Heart," released in 1970, is a light, cheesy love duet that offered the perfect soundtrack to everyone who'd fallen in love.

In 1969 the duet "Je t'aime... moi non plus," sung by French enfant terrible Serge Gainsbourg and British actor Jane Birkin, triggered strong emotions. Even without understanding French, the suggestive and breathy style of singing led it to being banned from radio in many countries. Yet millions of copies of the "forbidden fruit" single were sold.

This father-daughter duet might seem creepy to some: Natalie re-recorded her father's song "Unforgettable" in 1991, nearly 26 years after his death, singing on his original recordings. Natalie's duet with her "resurrected" late father was a smash hit: It sold 14 million copies and won seven Grammys.

How could this miraculous meeting ever have taken place? Well, in 2000 Karel Gott had released a German cover version of the 80s hit "Forever Young." The German gangster rapper was a fan of the pop hit and wanted to re-record it, this time as a duet with the Czech pop star. Rap meets Schlager. And "Forever Young" cracked the top five of the charts in 2002.

THE German dumbbell couple of the 70s; the two covered the hit from the musical Grease with John Travolta and Olivia Newton-John, "You're The One That I Want." The German version had nothing to do with disco, glamour and dance, though: Hallervorden and Feddersen squatted in the bathtub, played with rubber duckies and sang: "The bath is full, Hu Hu Hu."