As a musician, sad and angry song lover, and philosopher, I can testify to this. For me, music is the original “safe space”. I like loud, angry metal because it expresses emotions that if I were to personally let loose then people could get hurt.

Metal allowed me to safely express and feel my anger and frustration when a loved one was going through severe mental health issues. Therefore I was able to be supportive to said loved one, having already somewhat processed my own demons.

As for sad tunes, beauty is fleeting and that loss of something beautiful is universal to the human experience. I can’t explain why the intervals of minor scales stimulate those emotions. I do know I gravitate almost exclusively to minor scales when riffing on my guitar.

It could be that minor scales are just easier patterns to play around with on a guitar fretboard. I’m pretty sure there’s more to it than that though. As I’m playing, I feel the emotions guide me to those intervals and patterns. Other scales, especially the major scales, just don’t pack the same punch.