Mostly I just wondered if there is any advice. I guess my question is this. When writing a certain genre of a song ie indie and heavy metal are completely different, are there certain chords that tend to suit a certain genre - for example D more likely found in indie than in heavy metal? Or are there no rules really for what group of chords are perfectly indie, and what chords are perfectly heavy or emo?
I just wondered what you guys thought. I started writing this song for a girl 2 weeks ago I got the words down and the start of a melody for a smoking verse, but my chorus is still not as I want it to be. It's written but uses a random D chord instead of a minor chord - and I don't know if it really works. The rest of my song is mostly using C and G chords, with the occasional F.
There's a difference between the "key" of a song and the chords used.

The key determines the root note which often the one that starts/ends the song and is the one the song naturally "resolves" to. There are no "rules" as to what keys work with certain genres and what don't - often it's easiest to go with what suits your voice best. You can spot some common features though which are mostly there for practical reasons - for example: Jazz/Blues is often in "flat-ty" keys such as Bb and Eb because those notes are what most brass is tuned to. Lots of "chuggy" metal will be in E (or downtuned to D/C#) because that lets you "chug" on the open low E string. Since guitars can change key more easily with tuning/capos than trumpets can by adding extra tubing; the guitar is often changed to suit the other instruments.
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