I was explaining this to somebody the other day actually.
I'll use A minor and C major since they're a great example. Basically to sound like you're playing in either one you need to establish tonality. You have to establish which key your in based on the notes you play.
If you're writing something in A minor (a,b,c,d,e,f,g,a) there's kind of a hierarchy in terms of value that each note has. The higher the notes value then the more it indicates what key your in. (Sorry if this doesn't make a lot of sense)
But the heirarchy usually goes, 1,5,4,6,3,2,7 (some people would say it's 1,5,4,6,2,3,7 - there's a fair amount of debate on it)
These are essentially notes that you should keep coming back to in that order.
So if you have a melody line you should try to make your last note A, if you can't do that you should try to make it the fifth, which here is e, if you can't do that, try to make it the fourth which is d, if that's not possible, go for f...etc
Basically the more you come back to A and use the more key defining notes and chords then the more sad your song will sound.
You've got to use pulls as well. (sorry don't know the technical term for this) but if you play the 4th of a scale it'll feel like it should move up to 5, it's important to let it to establish key, equally if you play the 5th it'll feel like going to 1, you should let it, to establish key, sometimes you can ignore the pulls but only if you feel you've established the key already. 7 has a great pull to 8, it's a really common one to use in melody lines.
Also, all chord sequences establish tonality in some way or another.
4-5-1 is the most powerful chord sequence for establishing tonality and letting people know what key you're in. 6-1-3 is good too. I think I've heard 6-2-5-1 being used pretty effectively to establish key too. Going from 4-1 is like a really really standard chord movement in dubstep. It's pretty good for establishing key too.
antics wrote:Patterns using minors normally descend rather than ascend i do believe.
It all depends on the feel you want to achieve. I've written and heard lots of minor songs that go up. I tend to try to make everything move in different directions. First thing I learned while doing theory was to never let every instrument move in the same direction. Piano teacher used to tell me off constantly for writing stuff that moved all in one direction, lol. She hated it. You can ignore this rule, but it's a good idea to not move everything in one direction. Moving everything in one direction sounds good, but it feels clunky and unwieldy sometimes.
Hope some of this helps.
Also, somebody said about playing the 7th, that works in jazz, but you'll have more difficulty utilizing the 7th as a chord in dubstep. Unless you're going for a dark sound or jazzy sound lol.
EDIT: should also say, all those rules are really just guidelines, if you feel your tonality is established and your song sounds sad, then you can ignore them but they're good tools for establishing tonality.
EDIT II: On pulls
7 pulls to 8
4-5
5-1
2-3
Those are the important ones, can't remember if I listed them all.