Question: Which American singer and guest star on Austin & Ally performed the song It's Goin' Down in the 2017 film Descendants 2?
Context: A guest star (singer) looks for one of seven people to sing featuring, attempt to guess if each contestant is either a "Singer Lovely Voice" and a "Singer Loud Voice" (mystery singer), the guest, skilled vocalist and tone-deaf has to listening singer in 1-2 seconds.  The guest, tone-deaf and skilled vocalist has to take singer think sing to distorted out by listening sound in 1-2 seconds each round (the singer has to answer sound to lovely voice or loud voice).  Eliminated contestants will then reveal their singing ability and remaining the last person sing a song with guest successfully. Thomas Doherty (born April 21, 1995) is a Scottish actor, best known for his roles as Harry Hook in Disney's "Descendants 2" and as Sean in the British musical drama sitcom, "The Lodge".  In 2017, it was announced that Doherty would play the role of Zander in Michael Damian's film, High Strung: Free Dance. Josann McGibbon is an American screenwriter working in partnership with Sara Parriott.  The team's first major success as a screenwriter was the early Brad Pitt film, "The Favor".  Their biggest hits since then include "Three Men and a Little Lady" and "Runaway Bride".  In 2007, McGibbon and Parriott co-wrote and produced the hit Debra Messing miniseries, "The Starter Wife".  "The Starter Wife" received 10 Emmy nominations in 2007, including for best screenwriting, and won one Emmy Award.  It was also nominated for Golden Globe and Writers Guild awards, and was then produced as a series, also on USA Network.  McGibbon and Parriott wrote and co-produced the Disney Channel movie, "Descendants" which was directed by Kenny Ortega and premiered in July, 2015.  On February, 2013, it won the Writers Guild of America Award in television for Outstanding Children's Long Form.  They then wrote and executive-produced "Descendants 2", also directed by Kenny Ortega, which was simulcast on the Disney Channel, ABC, and the other cable channels owned by Disney-ABC in July, 2017. Anna Cathcart (  2003 ) is a Canadian actress, best known for playing Agent Olympia in the TVOKids/PBS Kids comedy series "Odd Squad" and its film spin-off.  In 2017, Cathcart portrayed Dizzy Tremaine in the Disney Channel musical fantasy film "Descendants 2", and will portray Kitty Covey in the upcoming film adaptation of Jenny Han's young adult romance novel "To All the Boys I've Loved Before". Dove Cameron (born Chloe Celeste Hosterman; January 15, 1996) is an American actress and singer, best known for playing a dual role as both title characters in the Disney Channel teen sitcom "Liv and Maddie" and starring in "Descendants" as Mal, daughter of Maleficent.  She reprised her role as Mal in "Descendants 2", which premiered on July 21, 2017, on Disney Channel. "Chillin' Like a Villain" is a song from Disney Channel's 2017 television film "Descendants 2", whose music and lyrics were composed by Antonina Armato, Tim James, Tom Sturges and Adam Schmalholz.  The song was performed in the film by the cast – Sofia Carson, Cameron Boyce, Booboo Stewart and Mitchell Hope– in their vocal roles as Evie (daughter of The Evil Queen), Carlos (son of Cruella de Vil), Jay (son of Jafar) and Ben (son of Belle and Beast).  The song peaked at number 95 in the Billboard Hot 100. Descendants 2 is a Disney Channel Original Movie that premiered on July 21, 2017 on Disney Channel, and was simulcast on Disney-owned networks ABC, Disney XD, Freeform, Lifetime and Lifetime Movies.  It is the sequel to the 2015 film "Descendants".  The film stars Dove Cameron, Cameron Boyce, Sofia Carson, Booboo Stewart, Mitchell Hope and China Anne McClain. "I'm Goin' Down" is a song written and performed by American singer Bruce Springsteen that was released as the sixth single from his album "Born in the U.S.A." in August 1985.  The song is one of several of the album's tracks that he recorded with the E Street Band in May 1982 at the Power Station music studio.  The release of these full-band tracks was put into question when Springsteen used solo material for his September 1982 LP, "Nebraska", and considered doing the same for his next album, which would become "Born in the U.S.A." He later decided to use several of the May 1982 recordings on "Born in the U.S.A." "I'm Goin' Down" beat out contender "Pink Cadillac" for a spot on the album. "It's Goin' Down" is a song from Disney Channel's 2017 television film "Descendants 2", whose music and lyrics were composed by Antonina Armato, Tim James, Tom Sturges and Adam Schmalholz.  The song was performed in the film by Dove Cameron, Sofia Carson, Cameron Boyce, Booboo Stewart, China Anne McClain, Mitchell Hope, Thomas Doherty and Dylan Playfair.  The song peaked at number 77 in the Billboard Hot 100. Sofía Daccarett Char, better known as Sofia Carson (born April 10, 1993), is an American singer and actress.  Her first appearance on television was as a guest star on the Disney Channel show, "Austin & Ally".  In 2015, she appeared as Evie, the daughter of the Evil Queen, in the Disney Channel Original Movie, "Descendants" and reprised her role in its 2017 sequel, "Descendants 2".  In 2016, she appeared as Lola Perez in "Adventures in Babysitting", Melanie Sanchez in "" and Tessa in "".
Answer: Sofia Carson