Tension

Exactly. While it's still good to learn these things, you should never get to the point where you're saying "Ok I'm trying to create tension so i'll use an augmented 6th". You should really think about what you're wanting to create, and write it from YOU. Not from a theory book.

-Chris

Thanks for the site, it will really help me. I know what everyone means when they say don't just write something because a book said to. However, in a part that I am writing I've tried lots of note clusters, but have not found the sound I want, so I figured maybe there was a chord that I didn't know about that could help me. Thanks everyone who helped me with my problem.

I use to think that clusters could get everything that I wanted, then I found intervals