Rihanna New Song 2015 With Kanye West, Paul McCartney: 'Four Five Seconds' Released After Long Absence

After missing in action for two years, Rihanna has finally launched a comeback, enlisting the talents of Kanye West and Sir Paul McCartney.

The 26-year-old singer recently released an acoustic ballad titled "Four Five Seconds," which was first heard when West previewed it at the Heart Music summit, the Daily Mirror reported.

RiRi and the rapper can be heard taking over the vocals while the former Beatle mans the guitar in the country-tinged track.

Without the help of electronic voice effects and uptempo sound beats, Rihanna went back to basics and showed off her unique sound.

The new song is the first taste of what we can expect from Rihanna's upcoming eighth studio album, which is due to be released later this year. The new album will be Rihanna's eighth.

Rumors have been circulating that RiRi has been working with John Newman and Calvin Harris as she puts together her latest musical offering.

Rihanna's last album, "Unapologetic," was released back in 2012.

Rihanna's new song gave West and McCartney a second chance to collaborate with each other after their first track "Only One," which would be the "publicly available recording from what has become a prolific musical collaboration between these two legendary artists," the Rollingstone magazine said.

Eventhough rapper Ty Dolla $ign told Billboard that the song would likely appear on West's upcoming album, it is still not known whether "Four Five Seconds" will appear on West's next album, or Rihanna's.

There also seems to be no confirmation yet whether the track was just an offshoot of the never-meant-to-be-heard result of three people tooling around on their Macbooks.

Aside from the new single, Rihanna also released promo pictures of the three singers wearing matching denim with Rihanna showing off her bare shoulder.

RiRi made her big announcement on Twitter on Sunday, writing: "FIRST GLIMPSE AT MY NEW MUSIC!!!" alongside a link to her website.