Sometimes I'm not completely sure when a song is a "rock song" or when it is from another music genre or even a "something-rock" song. How do you recognize it? Is it some bass rhythm? Some chord progressions? Some guitar picking pattern? The instruments? Some scale?
I find myself very confused with this. The rock in the 50's doesn't really have much to do with what people say it's rock in this days, and I even confuse some other genres with "rock" or "rock-something".
I liked a lot the music from Nirvana for example, and for me and a lot of people that was rock, until I discovered it was grunge which is a subgenre of a subgenre, inspired by other genres and so on...
Is there a way to recognize it by paying attention to some characteristic of the melody, or is it just the feel of it?
I looked in wikipedia and there are more than two hundred subgenres of rock, a lot of them mixed with other genres and stuff, so how do you know a song is a rock song, or that a group is a rock group?
Is there a simple or at least consistent way to know this?