Can you please tell me, how do you recognize the genre of a song?
For example, what is the difference between rock and hard rock or different versions of metal genres.
Is there any exact definition for different genres such as techno, hiphop, rap, pop, country and ...?

That's a really good question, I wish I knew.

I always like to make sure my ID3's are filled out, and done correctly. However, when it comes to the genre I just leave it blank. I too have trouble telling the difference between 'Rock', 'Rock & Roll', 'Hard Rock', 'Alternative', 'Alt. Rock', etc. I think they just got carrierd away adding genres over time. The only one I feel comfortable with now is 'Soundtrack' =P

I can see it now -- in the next version of Winamp they'll have 'Soundtrack', 'Movie Theme', 'Sound Track'... =P

Firebrand

I agree with Watadoo. Sub-genres are for purists only.
And if you don't know what to put in the field, you can still type in "Other" ;)

Metal genres:
 

Since I'm bored and frustrated, I'll list a few of them here just to spread my frustration:

Heavy Metal
Rap Metal
Death Metal
Black Metal
Traditional Metal
Grindcore
Grind
Viking Metal
Epic Metal
Heroic Metal
Avantgarde Metal
Gothic Metal
Doom
Melodic Black Metal
Melodic Death Metal
The Gothenburg Metal
Power Metal
Trend Metal
MTV Metal
Mood Metal
Experimental Metal
Industrial Metal
Techno-Metal
Folk Metal
Space Metal
Romantic Metal

...and that's barely a half of 'em. How on earth can you separete all those subgenres? It's impossible.

Well Colonel G, the list in a combo box under file info in the playlist in winamp program is also a good reference for genres, and thank you for those different metal genres that you mentioned :)
My question was, how to recognize the difference between different genres specially those which are a little bit similar to each other such as rock and hard rock and of course this huge list of metal genres.

Personally, I just hit cdnow.com and see what genre they classified it as (assuming they have the artist and album listed, of course). As far as those metal genres go, I'll see what I can do w/ some of them.

Rap Metal - Metal with rap/hip-hop styled lyrics and beats
Death Metal - characterized by extremely fast guitar and drum playing (often the same few chords), and harsh guttural vocals....Cannibal Corpse is a good example of this
Black Metal - Not quite at the levels of Death Metal, but still has a very dark mood to the music
Melodic Black/Death Metal - Black/Death Metal with lots of intricate and melodic guitar playing....In Flames and Quo Vadis are both good examples of this
Experimental Metal - Metal that doesn't really fit into any of the predefined metal subgenres, or metal that is trying new things musically that most metal bands wouldn't think to try
Industrial Metal - Metal combined with industrial music
Techno-Metal - Metal combined with techno (*shudder*)

These are the descriptions that pop into my mind when I hear someone classify a band as being one of these sub genres. Other people may have different interpretations.

-chizad

who in the hell even regulates what goes into a ID3 tag??

I think that each genre was divided into sub-genres as more bands made music that didn't fit exactly in the other genres. There is little difference between most of them that I can tell but I'm not into any specific genre. I guess people just want to be differen too.
btw: what is Ska?

i don't know what half those Genres are. Thats why i leave 'em blank

it comes with experience.....more you listen different genres of music better you can differentiate between them :)

ya know... this haas probably been one of the best threads that actually asked a good question.

That's easy. Grab "One Step Beyond" by Madness. Hear that "chick-a-chick chick-a-chuck" backbeat? That's the Ska Cliche. You can find it in pretty much every Ska song out there (Like most of Madness' & Specials (The)'s songs)

Oh, and to throw the cat amongst the pigeons, what's described as "Death Metal" above, I know as "Thrash Metal"... :)

A Sub-Genre of Country and Rap: Crap
 

One thing is for sure; if it has guitar, it is not classical.

With the exception of small ensembles that use a "Classical Guitar"