Question: Which choir collaborated on a mix tape that was produced among others by the group The Social Experiment and that featured the song "Angels"?

Context paragraphs:
Angels (Chance the Rapper song): "Angels" is a song by American hip hop recording artist Chance the Rapper.  The song was released on October 27, 2015 as the lead single from his third solo mixtape, "Coloring Book" (2016).  The track, produced by Lido and The Social Experiment, features vocal by fellow Chicago rapper Saba.

Coloring Book (mixtape): Coloring Book is the third mixtape by American rapper Chance the Rapper.  It was produced by his group The Social Experiment, Lido, and Kaytranada, among others.  For the album, Chance also collaborated with musicians such as Kanye West, Young Thug, Francis and the Lights, Justin Bieber, Kirk Franklin, and the Chicago Children's Choir.

The Button (Reddit): The Button was an online meta-game and social experiment that featured an online button and 60 second countdown timer that would reset each time the button was pressed.  The experiment was hosted on the social networking website Reddit beginning on 1 April 2015 (April Fools' Day) and was active until 5 June 2015.  The game was started by a Reddit administrator.

Eeves: Formed in 2010, in a short space of time Eeves have already secured BBC Introducing play from Tom Robinson along with many local and national radio stations rotation.  The band’s debut EP featuring 4 tracks was released 25 March 2012 when it was picked up by BBC Introducing and their track "Eyes Closed" was featured on BBC 6 Music Mix tape they were also asked to perform as part of Evolution Emerging Festival which they happily accepted, the band are currently working on their debut album.

The Mix Tape (MC Breed album): The Mix Tape is a compilation album released by MC Breed.  It was released on September 28, 2004 for Ichiban Records and was produced by DJ Crunk Mix and Mark Watson.

Last Dollar (Fly Away): "Last Dollar (Fly Away)" is a song written by Big Kenny, one half of the duo Big & Rich, and performed by American country music artist Tim McGraw.  It was released in January 2007 as the first single from his album "Let It Go".  "Last Dollar (Fly Away)" reached Number One on the "Billboard" Hot Country Songs charts, becoming McGraw's first Number One country hit since "Back When" in late 2004.  Big Kenny later recorded the song for his 2010 album, "Big Kenny's Love Everybody Traveling Musical Medicine Show Mix Tape, Vol.  1".

Michael Ostrzyga: Michael Ostrzyga is a German Composer and Conductor based in Cologne.  He is known for his choral music in particular, being commissioned by festivals like the Schleswig-Holstein Musik Festival and performers like The Chamber Choir of Asia, the Finnish YL Male Voice Choir (Ylioppilaskunnan Laulajat), the Vienna Chamber Choir, Latvian Youth Choir "Kamēr..." and Chamber Choir Consono, among others.  His works are performed by ensembles like the Raschèr Saxophone Quartet, New Dublin Voices, the Australian Chamber Choir, Rheinisches Klavierduo, Swedish choirs Kammarkören Pro Musica and Allmänna Sången Neues Rheinisches Kammerorchester, The Choral Project (California) and SFA A Cappella Choir (Texas).

Glashaus (record producers): Glashaus is a music production team composed of brothers Dan and Tom Glashausser.  Dan went to New York University for classical piano/sound engineering and Tom studied classical guitar and composition at Manhattan School of Music.  Their songs have been recorded by Moxie Raia, Rachel Platten, Travie McCoy, Vic Mensa and Post Malone.  Engineering credits include Selena Gomez, Wiz Khalifa, Ty Dolla Sign and Steve Aoki among others.  They have spent a significant amount of time working with Freddy Wexler developing new artists Moxie Raia, Spencer Lee, Cruickshank and Charles Perry.  The brothers are best known for their work with Moxie, having accumulated over two million streams and reaching #1 on Hype Machine.  As well as being featured on Spotify's "New Music Friday" playlist.  They produced and co-wrote six songs on her mix tape, 931 which Raia is currently performing on Justin Bieber's Purpose World Tour.  Glashaus is published by The Brain Music.

Nico Segal: Nico Segal (born June 25, 1993), also known by his former stage name Donnie Trumpet, is an American trumpeter and record producer from Chicago, Illinois.  He is part of the hip hop collective SaveMoney with Chance the Rapper and Vic Mensa, among others.  He was a member of the band Kids These Days, which broke up in 2013, and currently performs in the band The Social Experiment.

Mack 10 discography: The discography of West Coast hip hop artist Mack 10 consists of eight studio albums, two compilation albums, twenty-two singles, and fifteen music videos.  He has also collaborated on two albums and was featured in two soundtrack albums.  After signing to Priority Records in 1995, Mack 10 released his self-titled debut album in June.  The album, produced by fellow rapper Ice Cube, saw considerable commercial success and went Gold in the US.  His prosperity continued when he released "Based on a True Story", which peaked at number fourteen on the US "Billboard" 200.  The rapper collaborated with Tha Dogg Pound to record "Nothin' But the Cavi Hit" which was released on the "Rhyme & Reason" soundtrack.  Mack 10's 1998 release, "The Recipe", was the rapper's third and final album to be certified Gold in the US by RIAA.  Mack 10's album sales began to decline after his first compilation album release, "Hoo-Bangin': The Mix Tape, Vol.  1".  His fourth studio album, "The Paper Route" (2000), debuted at number nineteen on the "Billboard" 200; however, it failed to earn the rapper any RIAA certifications.

Supporting paragraphs: Angels (Chance the Rapper song) Coloring Book (mixtape)
Answer: Chicago Children's Choir