I’m 50 and although I doubt many people would consider my taste “mellow” unless all the listen to is Slayer and death metal, I have to say I’m starting to listen to songs I used to like a lot before I got into heavy metal, back when I was 12 or 13.
The 2 bands I’ve really been listening to a lot have been Journey and Foreigner, The lead guitarist of Journey, Neal Schon is a great guitarist!!! In fact he’s so respected by metal guitarists that he was invited to, and accepted, a spot in the guitar solo to “Stars” which was heavy metal’s answer to “We Are The World.”