There are a number of ways, but the most common would be to list it under "Education" or "Certifications."
If you completed all four badges, the best way to list it on a resume would be under education, like this:
Complete Musician Program (Music Production, Ableton Live, Music Theory, and Composition), Punkademic Courses Online, [date completed]
If you only completed one, two, or three badged, the best way would be like this:
Online Music Education Courses: Ableton Live and Music Theory Badges Completed. Punkademic Courses Online [date completed]
The term "badge" in academic circles is gaining traction, and one that colleges are becoming familiar with. Many universities are offering "badge" programs, similar to this, in which someone can earn something smaller than a full degree, but more than a single course.