Question: Which Barbadian singer recorded the album Unapologetic which featured the song Right Now?

Context paragraphs:
Diamonds (Rihanna song): "Diamonds" is a song recorded by Barbadian singer Rihanna for her seventh studio album, "Unapologetic" (2012).  It was written by Sia Furler together with its producers, Benny Blanco and StarGate.  The song premiered on September 26, 2012, during the "Elvis Duran and the Morning Show" and was digitally released the following day as the lead single from "Unapologetic".  Def Jam Recordings serviced the single to contemporary hit radio in the United States on October 2.  "Diamonds" is a mid-tempo pop, electronic and R&B ballad that features heavy synthesizers, orchestral sounds and electronic rhythms.  The song's lyrics serve as a departure from the themes of unhealthy relationships that were on Rihanna's previous singles and contain a prominent concept of love.

Unapologetic: Unapologetic is the seventh studio album by Barbadian singer Rihanna.  It was released on November 19, 2012, by Def Jam Recordings and SRP Records.  It was recorded between June and November 2012, during promotion of her sixth album, "Talk That Talk" (2011).  As executive producer, Rihanna enlisted previous collaborators The-Dream, David Guetta, Chase & Status, and StarGate to work alongside new collaborators such as Parker Ighile, Mike Will Made-It, and Labrinth.  "Unapologetic" is mainly a pop, dubstep and R&B album that incorporates elements of hip hop, EDM and reggae in its production, similar to the sound of her previous albums "Talk That Talk" and "Rated R" (2009).

Love Without Tragedy / Mother Mary: "Love Without Tragedy / Mother Mary" is a song recorded by Barbadian singer Rihanna for her seventh studio album "Unapologetic" (2012).  She co-wrote the song with its producers Terius Nash and Carlos "Los" McKinney.  An electro-R&B, Electronica and new wave song, the two songs derive its musical structure from the genres of electronica and new wave.  Lyrically, "Love Without Tragedy" is love-oriented while in "Mother Mary" the singer makes a confession about a moment in her life which she regrets.

Right Now (Rihanna song): "Right Now" is a song by Barbadian recording artist Rihanna from her seventh studio album, "Unapologetic" (2012).  The song features French disc jockey David Guetta.  Rihanna co-wrote the song with R&B singers Ne-Yo and The-Dream, while their longtime collaborators, Norwegian production duo StarGate, co-produced the track alongside Guetta and his own longtime collaborators Nicky Romero and Giorgio Tuinfort.  It was sent to contemporary hit and rhythmic radios in the United States as the fourth international single and fifth overall from the album on May 28, 2013.  Musically, "Right Now" is an EDM song.  The lyrical content features Rihanna chanting to live life in the moment.

Half of Me (Rihanna song): "Half of Me" is a song recorded by Barbadian recording artist Rihanna for her seventh studio album "Unapologetic" (2012).  It was written by Emeli Sandé, Naughty Boy and Stargate, with production done by the latter two.  It is a chamber pop and R&B song that sees Rihanna deliver vocals in an "experimental" fashion.  Its lyrics have been described as a "personal essay", with lyrics that discuss Rihanna's unrepentant attitude in letting people into her life.  She references Oprah Winfrey in the line "You saw me on the television".  The song garnered positive reviews from music critics, some of whom felt that it is "heartfelt" and "psychedelic".  Upon the release of "Unapologetic", the song charted in Canada, France, Ireland, Switzerland and the United Kingdom.  It debuted at number 10 on the UK R&B Chart.

Nobody's Business (song): "Nobody's Business" is a song recorded by Barbadian singer Rihanna for her seventh studio album "Unapologetic" (2012).  Co-written by Rihanna together with its producers Terius "The-Dream" Nash and Carlos "Los" McKinney, it features guest vocals by American singer Chris Brown.  It is their third collaboration following the domestic violence case that happened between them in 2009.  "Nobody's Business" is a disco-pop and R&B-funk song that mixes Chicago stepping and house styles and features strings, piano, and a four-on-the-floor kick drum.  It contains interpolation of the 1987 single "The Way You Make Me Feel" by Michael Jackson.

No Love Allowed: "No Love Allowed" is a song recorded by Barbadian singer Rihanna for her seventh studio album, "Unapologetic" (2012).  The singer co-wrote the track together with Sean "Elijah Blake" Fenton, Alexander Izquierdo, Steve Wyreman and Ernest Wilson, who produced it under his production name No I.D..  Kuk Harrell and Marcos Tovar recorded the song at Record One Studios and Westlake Recording Studios in Los Angeles and Metropolis Studios in London; Harrell also did the vocal production.  "No Love Allowed" is a electro-ragga and reggae song with an instrumentation consisting of a bubbly, dubbed-out groove, Caribbean and dubstep beat and loping drumless rhythms.

What Now (song): "What Now" is a song recorded by Barbadian singer Rihanna for her seventh studio album, "Unapologetic" (2012).  It was written by Olivia Waithe, Parker Ighile and Nathan Cassells alongside Rihanna, with production handled by Ighile and Cassells.  A remix collection was released exclusively to Beatport on August 29, 2013 and later via iTunes, Amazon, and Google Play on September 17, 2013.  The single was serviced to US rhythmic radio on September 24, 2013, before impacting mainstream radio on October 1, 2013 as the fifth international single and sixth overall from "Unapologetic".  Another remix collection was released to Beatport on October 29, 2013.  The song is a mid-tempo piano ballad which incorporates sounds which resemble "sonic bombs" during the chorus and "crashing" drums.

Jump (Rihanna song): "Jump" is a song recorded by Barbadian singer Rihanna for her seventh studio album, "Unapologetic" (2012).  It was written by Kevin Cossom, M. B. Williams, StarGate and Chase & Status, with production done by the latter two and Kuk Harrell.  It samples the lyrics of the 1996 single "Pony", performed by Ginuwine.  Its composition and structure received comparisons to not only Justin Timberlake's song "Cry Me a River" and Magnetic Man's "I Need Air", but also to some of Rihanna's previous songs, including "Rude Boy" and "Red Lipstick".  A remix of the song called "Jump (Club Cheval Rap Remix)" by rapper Theophilus London was leaked onto the internet.  "Jump" was serviced to Australian radio on January 24, 2014 as the album's fifth Australian single and seventh overall.

Stay (Rihanna song): "Stay" is a song recorded by Barbadian singer Rihanna for her seventh studio album, "Unapologetic" (2012).  It features guest vocals by Mikky Ekko, and was released as the second single from the album on January 7, 2013.  "Stay" was co-written by Ekko and Justin Parker.  The song's lyrical content speaks of temptation and the inability to resist true love.  Music critics were generally positive in their opinion regarding the balladry, with most describing it as a standout track on the album, though a few labeled it as boring.  The song was featured on the third-season finale of the TV Show Younger.

Supporting paragraphs: Right Now (Rihanna song) Unapologetic
Answer: Rihanna