It’s hard to think of a more quintessentially summertime subgenre than ’80s hard rock. Colloquially known as glam metal (or, more derisively, the dreaded “hair metal”), these songs celebrate life’s simple-but-universal pleasures: soaking up the sun, throwing a blowout party and congregating around the nearest radio to blast your favorite tunes. The ’80s are long gone, but these sentiments are eternal — and that’s why you need The 20 Best ’80s Hard Rock Summer Songs on your next playlist. 20. Motley Crue, “Kickstart My Heart” The connection between getting a shot of adrenaline to the heart afte…