Listen to the calming music. The dots show the loud/important notes and the background/soft notes. (See notes) Anyway, the tags pretty much sum it up.
This uses a Pentatonic scale, that has notes that can be minor or major. Each note randomly gets louder or softer, creating important notes (the loud notes) and background notes (the soft notes). It creates this calming effect by gradually changing the background notes into important ones, and important notes into background.
