One song to introduce someone to a band

[Trollheart]

Think you can do it? Pick just ONE song --- with accompanying YT --- to show what a band you're into is like. It's harder than you think. To be fair, many bands go through phases, like when they change their singer, or head in a new musical direction, so you can use one song per phase, let's say.

My own idea of how to get someone into Sabbath:

OZZY era
War pigs (from "Paranoid")


DIO era
Heaven and Hell (from "Heaven and Hell")