Let's do this right with no faggy hair metal or grunge tards...
Rush (started out as hard rock and hard progressive rock)
BTO (listen to songs like "Not Fragile" and "Welcome Home")
Scorpions (old stuff before the dark times,before metal)
Queen (if you don't think so it's because you haven't listened closely enough)
Ozzy with Randy
Van Halen (the original Van Halen only)
Hard Rock is very closely associated with rock,classic rock,progressive rock and progressive hard rock,as well as with psychedelic or "acid" rock and "Southern Rock" as well.
If your girlfriend likes it then it might be rock or classic rock or pop rock or maybe Southern Rock.But if your girlfriend says "can we listen to something else?" then it's probably too hard for her ears,too long,too progressive and has too many solos for her.Hence, "Hard Rock."
All rock is good as long as we're talking about classic rock which really is what all of this is.Classic being pre-Mtv rock and hard rock and southern rock and prog rock and prog hard rock and acid rock or psychedelic rock,but not really metal except for maybe barely a litle bit.Bands that were rock or hard rock or metal before Mtv could still pass as classic rock.If I had to list all classic rock bands then I would be here for fucking ever.
HARD ROCK could also be thoughtful or intelligent and not just stuck in rowdy or controversial mode all of the time like how many of today's shoddy imitators like to think of it as being. --- hard rock --> Heartbreaker (Led Zeppelin),Miss Misery (Nazareth),Free For All (Ted Nugent),Stranglehold (Ted Nugent),Back In The Saddle (Aerosmith),Freewill (Rush),Barracuda (Heart),Black Dog (Led Zeppelin),Back from the Storm (Hendrix),
Helter Skelter (Beatles),TNT (ACDC),Susie Q (CCR),
Frankenstein (Edgar Winter Group),Godzilla (Blue Oyster Cult),Cities On Flame (Blue Oyster Cult),Hocus Pocus (Focus),School's Out (Alice Cooper)
-not hard rock, not no way, not no how-> def leppard,gnr and motley crue, uh-uh...forget about it -> motley crue popularized glam/hair metal and gnr was the last popular glam/hair metal band, while def leppard was somewhere in the middle during the full bloom of bloomin' fairy metal.