Episode 1 contains an introduction and Yoon Jongshin deciding on a hypothetical client.
Episode 2 (not subtitled)
Episode 3 contains Yoon Jongshin researching about BTS.
Yoon Jongshin recruits the help of PERC%NT (artist and producer at MYSTIC, who is also apparently an ARMY) to learn more about BTS.
Yoon Jongshin and PERC%NT compose a group song for BTS.
Yoon Jongshin and lyricist Kang Hwaseong compose a ballad for BTS' vocal line.
Yoon Jongshin and lyricist Kang Hwaseong compose a ballad for BTS' vocal line part 2.
Yoon Jongshin and PERC%NT work on the arrangement and completing the demo.
Yoon Jongshin writes lyrics for the two songs.
Source: 월간 윤종신 1, 2, 3, 4, 5, 6, 7, 8, and 9
Turn on 'CC' for subtitles. Big Hit did not commission Yoon Jongshin to write songs for BTS, this is a Youtube series started by Yoon Jongshin to show the behind the scenes process of creating a demo, using BTS as a hypothetical client.