Question: Are Ricky Ross and Jeon Ji-yoon both singers?

Context articles: The Undeveloped Heart EP
Kwon So-hyun
Jeon Ji-yoon
Fergus Sings the Blues
H-Logic
Ricky Ross (musician)
New Recording
4Minute
So Long Ago
What You Are (album)

The Undeveloped Heart EP is the sole single/EP release from Scottish rock musician Ricky Ross' album "New Recording".
 It contains a new version of "The Undeveloped Heart", which was originally recorded by Ross' band Deacon Blue and re-recorded by Ross for "New Recording".
 The addition of a driving bass line and guitar to "The Undeveloped Heart (98 Remix)" completes the move of the song from its original form as an understated piano ballad to a track that sits fully in alternative rock territory.
Kwon So-hyun (born August 30, 1994), is a South Korean singer and actress.
 She was known as a member of the South Korean girl group 4Minute, under Cube Entertainment.
 She is also a former member of the South Korean girl group, Orange.
 Before June 15, 2016 (end of her contract with Cube), Sohyun left 4Minute and the record label along with members Nam Ji-hyun, Heo Ga-yoon, and Jeon Ji-yoon.
Jeon Ji-yoon (born October 15, 1990), better known mononymously as Jiyoon or by her stage name Jenyer, is a South Korean rapper, singer-songwriter and actress.
 She was previously a member of South Korean girl group 4Minute and its sub-group 2Yoon.
 She debuted as a solo artist on November 2, 2016, under the stage name Jenyer, with the release of her debut digital single, "I Do".
"Fergus Sings the Blues" is the third single from the album "When the World Knows Your Name" by the Scottish rock band Deacon Blue.
 Writer Ricky Ross has stated in an interview with Johnnie Walker that the song was inspired by "Gael's Blue" by Scottish singer-songwriter Michael Marra.
H-Logic is the fourth studio album by South Korean singer Lee Hyori, released on April 12, 2010.
 The album has 14 tracks, including collaborations with Daesung from Big Bang, Jeon Ji-yoon from 4Minute, Bekah from After School, Gary from Leessang, and Sangchu from Mighty Mouth.
 The singer worked also with E-Tribe, the team behind "U-Go-Girl", the lead single from her previous album.
Richard Alexander "Ricky" Ross (born 22 December 1957) is a Scottish singer-songwriter and broadcaster.
 He is the lead singer of the rock band Deacon Blue.
New Recording is a solo album from Scottish rock musician Ricky Ross and member of Deacon Blue.
 It was produced by Ross and former Love and Money keyboardist Paul McGeechan.
4Minute (Korean: 포미닛 ) was a five-member South Korean girl group formed in 2009 by Cube Entertainment with music singles and albums released primarily in South Korea and Japan.
 The members of the group were Nam Ji-hyun, Heo Ga-yoon, Jeon Ji-yoon, Kim Hyun-a, and Kwon So-hyun.
 The group debuted in June 2009 with its first single, "Hot Issue", and in December 2010, it released its first Japanese album, "Diamond".
 In 2011, the group released its first Korean full-length album, "4Minutes Left".
So Long Ago is the solo debut album from Scottish rock musician Ricky Ross.
 Ross later founded Deacon Blue.
What You Are is a solo album from Scottish rock musician Ricky Ross.
 It was the first solo album Ross released after the breakup of the band he fronted, Deacon Blue.