Question: Who is a current member of the group Guy, Aaron Hall or Matt Thiessen?

Context paragraphs:
Guy III (album): Guy III is the third and most recent studio album from American R&B group Guy, released January 25, 2000 on MCA Records.  The album peaked at number thirteen on the "Billboard" 200 chart.  At the time of its release, not all of the members were on the same page for the release of "Guy III".  Founding member Teddy Riley remained hopeful that his group Blackstreet would record another album despite the friction between him and group member Chauncey Hannibal.  Aaron Hall insisted on recording another solo album, while his brother Damion Hall was interested in an acting career.

Aaron Hall (singer): Aaron Hall (born August 10, 1964, The Bronx, New York City and growing up in Brooklyn and Roosevelt, Long Island), is an American soul singer and songwriter.  He is a current member of the group Guy, which he founded in the late 1980s, along with New jack swing producer Teddy Riley and songwriter Timmy Gatling, who was later replaced by Hall's brother Damion Hall.  In 1988, they released their debut album which went on to sell over a million copies being certified platinum.  Hall led the group in songs like "Groove Me", "I Like" and "Piece Of My Love".

The Future (Guy album): The Future is the second studio album from American R&B group Guy, released in November 13, 1990 on Uptown Records and MCA Records.  The album had a much darker tone in stark contrast to their debut.  Most of it had to do with things going on behind the scenes.  A year after the release of their debut album, they fired their manager Gene Griffin- who they claimed allocated funds from the group.  This revelation angered all of the members, and particularly infuriated lead singer Aaron Hall- so much so that he didn't sing on half of the album.  Hall revealed:

My Girlfriend (Relient K song): "My Girlfriend" is a song by the Christian rock band Relient K, released on their self-titled first album.  The song originally appeared as "Marilyn Manson Ate My Girlfriend" on the band's demo album, "All Work and No Play".  The song is about Marilyn Manson eating Matt Thiessen's girlfriend.  Thiessen wrote this song when he was 15 years old.  Thiessen has said that he wrote it because of a female friend, who lived eight hours away in Pennsylvania, who he would talk to about many things including spiritual matters such as where God was taking them in the future.  His friend would later turn from Christian music to Nine Inch Nails and Marilyn Manson.  In an interview with CCM Magazine Thiessen stated "through this she changed her lifestyle [and] what she believed in."  His friend would later be expelled from school and would be kicked out of her house and sent to a youth detention center.  Thiessen would later state "She felt that Christianity was stupid and just this big hypocrisy.  Being young and impressionable, I just wrote this little, stupid song, but that was the way I dealt with it—writing this song about how she got so consumed by Marilyn Manson."

Matt Thiessen: Matthew Arnold "Matt" Thiessen (born August 12, 1980) is a Canadian-American musician, singer and songwriter known for being co-founder, lead singer, guitarist, pianist, and primary songwriter for the Christian rock band Relient K.  With Relient K, he has released eight full-length albums, including three that were certified Gold, and three that peaked in the top twenty on the "Billboard" 200.  Outside of his work with Relient K, Thiessen maintains a low-profile side project called Matthew Thiessen and the Earthquakes.  In 2009, he co-produced and collaborated on Owl City's album "Ocean Eyes".

Rebuild (song): "Rebuild" is a song written by Jon Foreman of Switchfoot and Matt Thiessen of Relient K.  The song was written in conjunction with the bands' 2007 Appetite for Construction Tour, featuring members from all three bands on tour, Switchfoot, Relient K, and Ruth.  Thiessen sang second vocals, and Dustin Ruth of Ruth played harmonica.

More Like a Movie, Less Like Real Life: More Like a Movie, Less Like Real Life is the second EP from Australian band Ellington.  It was self-released in late 2008 and was recorded in the United States, with producer Matt Malpass at Marigold and Monsters studio.  It features guest vocals from Matt Thiessen (Relient K), Jeff Turner (Say Anything) and Leighton Antelman (Lydia).

Don't Be Afraid (Aaron Hall song): "Don't Be Afraid" is a song by American singer Aaron Hall.  It was produced by Hank Shocklee and Gary G-Wiz and spent two weeks at #1 on the US R&B chart (making it Aaron Hall's highest charting R&B hit) and peaked at #44 on the "Billboard" Hot 100.  It was one of the singles taken from the soundtrack for the 1992 film "Juice" starring 2Pac.

Damion Hall: Damion Hall, also known as Damion "Crazy Legs" Hall is an African-American R&B singer.  He is a member of the new jack swing group Guy and is the brother of Guy member, Aaron Hall.  He has released one solo album, Straight to the Point in 1994, which spawned one single, "Satisfy You", featuring Chanté Moore.  That song managed to reach #48 on the Billboard R&B charts.  He is currently unsigned.

Relient K: Relient K is an American rock band formed in 1998 in Canton, Ohio, by Matt Thiessen, Matt Hoopes, and Brian Pittman during the band members' third year in high school and their time at Malone University.  The band is named after guitarist Hoopes' automobile, a Plymouth Reliant K car, with the spelling intentionally altered to avoid trademark infringement over the "Reliant" name.

Supporting paragraphs: Aaron Hall (singer) Matt Thiessen
Answer: Aaron Hall