I said to a friend that one knows that it is good music if there are band photos and one of 'em is holding a cat. She pointed to the mustasches and the long hair and yes I agreed that hairy men + cat must be the ultimate to create good rock.
Hey it works for Mikael Åkerfeldt for instance, he's got many cats. ;)
I find the vocals a bit unusual for 70's hard rock, they are quite soft but it suits well since the riffing is pretty hard and I do like some variation of my 70's music, even though I guess I'd love it if everyone sounded like Deep Purple all the time as well.
Have a listen of some songs, I found a good video with pictures and info, check out the different type of album covers there as well: