Question: Are Justin Timberlake and Andrew Montgomery both singers?

Context articles: The Only Promise That Remains
Dick in a Box
Andrew Montgomery
Justin Timberlake: Live from London
Justin Timberlake
Dead and Gone
Love Dealer
Justin Timberlake videography
Rob Knox (producer-songwriter)
3-Way (The Golden Rule)

"The Only Promise That Remains" is a country duet recorded by American singers Reba McEntire and Justin Timberlake for McEntire's 24th studio album, "" (2007).
 It was written and produced by Timberlake, with additional writing from Matt Morris.
 McEntire and Timberlake met at the 49th Annual Grammy Awards ceremony in February 2007, where McEntire asked him to be a part of the album.
 She was initially skeptical when Timberlake suggested that he write a song for her, expecting it to be "something that was wayyy out of [her] ballpark".
 She was relieved when he played "The Only Promise That Remains", an acoustic-based Celtic love song, for her.
"Dick in a Box" is the debut single by American comedy troupe The Lonely Island, featuring singer Justin Timberlake.
 The song and music video debuted on "Saturday Night Live" as an "SNL" Digital Short on December 16, 2006.
 The video depicts two early-1990s R&B ballad singers Andy (Andy Samberg) and Raif (Justin Timberlake) crooning a holiday song about making a gift for their girlfriends of their penises wrapped in boxes (strategically placed) topped with bows.
Andrew Montgomery is a Scottish singer who is best known as a member of late '90s Aberdeen indie rock band Geneva.
Justin Timberlake: Live from London is the first live video album by American singer-songwriter Justin Timberlake.
 It was released on December 15, 2003, by Jive Records.
 It documents Timberlake's performance at the London Arena on May 18, 2003.
Justin Randall Timberlake (born January 31, 1981) is an American singer-songwriter, actor and record producer.
 Born and raised in Tennessee, he appeared on the television shows "Star Search" and "The All-New Mickey Mouse Club" as a child.
 In the late 1990s, Timberlake rose to prominence as one of the two lead vocalists and youngest member of NSYNC, which eventually became one of the best-selling boy bands of all time.
 Timberlake began to adopt a more mature image as an artist with the release of his debut solo album, the R&B-focused "Justified" (2002), which yielded the successful singles "Cry Me a River" and "Rock Your Body", and earned his first two Grammy Awards.
"Dead and Gone" is a song by American hip hop recording artist T.I., featuring American singer-songwriter Justin Timberlake.
 It was released as the eighth single from T.I.'s sixth studio album, "Paper Trail" (2008).
 Due to the high number of digital downloads upon the album's release, the song debuted on the "Billboard" Hot 100 before its official single release.
 The song marked the second collaboration between T.I. and Justin Timberlake, the first being the hit single "My Love", from Timberlake's second album, "FutureSex/LoveSounds" (2006).
 T.I. and Timberlake performed this song at the 51st Grammy Awards.
 The song was later nominated twice at the 52nd Grammy Awards, for Best Rap/Sung Collaboration and Best Rap Song.
 It was the 10th bestselling digital single of 2009 in the United States.
 As of 2012, it had sold 3.1 million copies in the country.
Love Dealer is Esmée Denters' third single from her debut album "Outta Here".
 The song was written by Denters, Justin Timberlake and production team StarGate in 2009.
 StarGate produced the song together with Justin Timberlake, who also provided featured vocals.
 On March 22, 2010, British radio station BBC Radio 1Xtra confirmed that "Love Dealer" would be Esmée Denters' next single off of "Outta Here".
 It was, however, her first official single in the US.
 The song was released in an attempt to help her break the US market with the help of Justin Timberlake.
 Due to a lack of airplay in the United Kingdom the single failed to reach the UK Top 40.
 It also failed to chart on the "Billboard" Hot 100.
American entertainer Justin Timberlake has released four video albums and has been featured in thirty-seven music videos, seventeen films, fifteen television shows, and six commercials.
 He achieved early fame when he appeared in the Disney Channel television series "The New Mickey Mouse Club", alongside singers Britney Spears and Christina Aguilera and actor Ryan Gosling.
 Timberlake rose to fame in the late 1990s as the lead singer of the boy band NSYNC.
 In 2002, he launched his solo career and released his solo debut single "Like I Love You", the music video for which was directed by Bucky Chrome.
 Francis Lawrence directed the video for "Cry Me a River".
 The video features Timberlake's character as he spies on a former lover, who according to the director portrays his former romantic interest Spears.
 At the 2003 MTV Video Music Awards, the video won the accolades for Best Male Video and Best Pop Video.
Robin Tadross (born August 8, 1980), professionally known as Rob Knox, Is an American record producer and songwriter.
 He is best known for working with artists including Justin Timberlake, Lil Wayne, T.I.
, Rihanna, Britney Spears and Chris Brown.
 Knox has produced singles including "Dead and Gone" by T.I and Justin Timberlake and "Love Sex Magic" by Ciara and Justin Timberlake.
"3-Way (The Golden Rule)" is a song recorded by American comedy music group The Lonely Island featuring American singers Justin Timberlake and Lady Gaga.
 It appeared as an SNL Digital Short in the May 21, 2011 episode of the sketch comedy television series "Saturday Night Live" ("SNL"), which saw Timberlake and Gaga as the host and musical guest, respectively.
 It was released as a single on May 24, three days after the broadcast.
 The R&B song was written by Andy Samberg, Akiva Schaffer, Jorma Taccone, and Timberlake while produced by The Futuristics with additional production from Asa Taccone and Ryan & Smitty.
 Samberg and Timberlake were nervous about presenting the idea to Gaga, who initially failed to find the humour in the song.