What are some of the essential music theory concepts to memorize?
I just started looking at music theory earlier this week, and I have to admit that it's pretty overwhelming especially since my only background involves playing the guitar--basic chords, playing songs by tabs, etc. Also, I realized how useful music sheet notation is. It abstracts away from the instrument and has an immediate focus on theory. But I'm not quite sure what's essential and what's not. Of course, this depends on the goals of the learner. My goal is to be able to compose with enough theoretical background. I don't plan to write sheet music, take music classes (although I'm taking a few online classes on coursera), or play the instrument proficiently by any means. What I want to do is analyze the songs that I like and ask myself why I like it in order to achieve my end goal, which again is to compose music.
This is my progress so far:
I'm confident in reading the treble clef, but is reading the bass clef necessary? Rhythm seems rather useless also.
I'm using a midi keyboard so I can apply what I learned (I don't have the fretboard memorized, so I decided to take this path). Someone mentioned that in order to get the intervals down on the piano, I should just learn the 5th interval from each key. I noticed a pattern and it stuck, and it's allowing me to find other intervals with ease. Any other tips?
The intervals of the various triads, 7 chords, and sus chords. Would you guys add something here?
And things I plan to do (or maybe not depending on your opinion):
Learn the 10 essential scales (7 modes and a few others like the altered). I don't think I really need to know them at the top of my head, but taking note of what notes they're comprised of should be enough to know which notes I can play when I see a certain chord. My goal doesn't involve improvising, and I can afford to make time to think.
Learn the different key signatures and their relative keys.
Learn the chord progressions for major and minor keys. The basic I-VII pattern.
Hopefully by now I can finally understand the use for borrowing/applying chords and learn their use cases.
Do you guys have any suggestions? Additions you'd like to make? I was actually inspired by the last todo item to ask this question, and the reason is because while I understand it, I can't see the bigger picture in terms of applying it to my own composition. I'm juggling a lot of concepts in my head (which is great for learning imo), but while I'm at it, I'd like to add more todos so I'm constantly overwhelmed.