Years before he would become famous as the frontman of arena-conquering, festival-headlining Scottish alt-rock heroes Biffy Clyro, Simon Neil was a kid infatuated with a cassette. He still owns it, the same one he rushed from school to buy on the day it came out.

To say that he knows Nirvana’s MTV Unplugged In New York off by heart simply wouldn’t go far enough. On the cusp of entering his teenage years, he would ritually cover it with his friends, ...