80's music consisted mostly of whiny guitars, semi-human(as in: never too masculine) voices and better lyrics in general than most/all of the hip-hop/pop songs that you will find on the radio today. Chances are, if the music sounds like a cross between innocently thundering guitars and lukewarm/strong drugs, it's 80's music. If there's a music video involving a singer with a spectacular vocal range and hair combed halfway up to the ceiling dancing on a stage with horrid patterns on his skin-tight outfit, it's 80's music. If you're too young understand the political references in the lyrics or just old enough to remember what they were about, it's 80's music. If a man wearing an 'I love the 80's!' t-shirt suddenly looks up at the supermarket and names a Duran Duran song to the nearest person, it's 80's music. If you go to amazon or e-bay and type '80's music' into the search field, it's 80's music. No, really, it's true.
Kid wearing a Pink Floyd shirt: Woah, that's so 80's music!