Titled Four, Five Seconds, the new track features Rihanna, Kanye West and Sir Paul McCartney. The Barbadian pop star casually accompanied the surprise release with a tweet that read "First glimpse at my new music!!!" leaving fans a little open-mouthed when they clicked the link and realised who the 26-year-old has partnered with for said 'new music'.

The promo visual for the new single (pictured above) features all three stars clad in denim, with brooding faces and McCartney clinging on to his iconic guitar.

Musically, the new song is a million miles away from the material we are used to hearing from both Rihanna and Kanye West, which leaves us thinking that perhaps McCartney was in the driving seat in the studio session, which saw the three stars unite for the surprise release. The acoustic, paired-back song is very much done in Paul McCartney's style – letting the lyrics and the soothing beats do the talking. Just one acoustic guitar and an organ feature on Four, Five Seconds – showcasing Rihanna and West's vocals in a way that their usually 'club-ready' 'anthems' don't allow for.

Rihanna and West have previously collaborated for Jay Z's Run This Town – which was one of the star singles of Mr. Beyonce's Blueprint 3 album. Two years later the duo partnered up again, this time with Rihanna singing a hook for All Of The Lightsa single from Kanye's My Beautiful Dark Twisted Fantasy album – ten other artists featured on the track (including Fergie, John Legend and even Elton John) and the song went on to win a Grammy.

Of course, this also is not the first time that West has collaborated with McCartney. The duo caused a media frenzy recently when they released another surprise track Only One, which West would later explain is an ode to he and Kim Kardashian's only daughter: North West –sung through the point of view of his late, beloved mother Donda.

Four, Five Seconds by Rihanna featuring Kanye West and Paul McCartney is available for download at rihannanow.com and the iTunes store now