Every day when I leave work, I pop in my earbuds and throw on my favorite playlist. As I walk down the block to catch my train home, my mood steadily improves. While the music drowns out all other sound, I find myself feeling less and less hostile toward the inane actions of fellow commuters, and by the time I get home and throw my phone on the couch, I’m actually happy (weird). But music, it turns out, affects your brain the same way that exercise and taking opioid drugs do: It gets you high.