The project provides free EFL/ESL materials. Teach classes using pop songs, followed by artificial immersion homework.   https://www.eflsongs.com

In a Nutshell

Classroom learning can be re-triggered subconsciously via homework assignments. In this case, through playlist pedagogy: hearing (not necessarily even listening to) the song under normal daily life conditions. For example, random loading of the target song on a Spotify playlist, will trigger memories of the learning activity. This re-enforces the original learning: days and weeks after the class lesson has finished. Furthermore, using one song to teach multiple learning points can have compounding multiplier effects. 

Playlist Pedagogy = A Layered Language Learning Method.

The idea is that learning can be layered into everyday activity. This is how overseas immersion works. Listening to songs is a common daily life activity for many people across all generations. Using songs, we are artificially creating an immersive experience in the student's home environment.