How Do I Create Some Form to My Music

Hello!

Other than my "pieces" sounding unpleasant, I always thought that there was something else that was off about them, and I guess it's because they do not have any "form". By that, I mean that they jump from one melody to another. I unconsciously do this. I also do not know how to resolve this problem. It often has to do with me not being able to create more variations of the melody; I run uninspired and so I either switch to another melody. 

The piece I attached to this post is a prime example of what I mean. It is technically not done, since there is some missing part from the largo section, but I was too frustrated by the lack of organization that I decided to stop and seek advice from here. 

It's a big topic because "form" can relate to genre. Classical form is easy enough to master. It's when you get into contemporary styles and/or "through composing" where things change. 

Your piece is basically tonal. In classical forms different melodies are often linked by "bridge passages" that usually involve changing key. It's a good place to start (because even if you write in a more modern style you need some transition to get to a new melody). Sometimes there's no bridge passage - pieces referred to as A-B-A etc where melody A ends in a cadence followed by B. Then when B has done melody A returns. Minuets with their trios are often like this.

Can I suggest therefore

1) that you study a few classical pieces: Mozart's Eine Kleine, Or if you're not happy with orchestral, try Mozart's Sonata in C, the famous one. (Mozart was quite good at music so he's reliable 😄 )

2) Learn enough theory to modulate to a related key - the dominant, subdominant, relative minor (submediant). You can save the surprise modulations for later! using diminished chords, the Neapolitan 6th, Augmented 6ths and so forth. (Again, the first movement of that Mozart Sonata is full of hints.)

3) Map out your phrasing. At first go for 2 or 4-bar chunks.

4) Study a few through-composed pieces - just intelligent listening may be enough. 

I suffer your pain - my sense of melody was almost killed by my partial college education. Thankfully it's gradually returning - and in a way I'm not unhappy because I don't want to compose rehashes of the classical era. So most of my stuff is through composed. To me, form is a matter of balance, proportion and contrast.

Good luck.

Quinn made some beautiful concrete remarks about how to handle form. We can also look to it in a more abstract manner. Chekhov's gun is a principle you can use in every artform that can work in favor for consistency, check it out and give it some thought, I'm sure it can help you with your problem: https://en.m.wikipedia.org/wiki/Chekhov's_gun

Music that develops that goes through different moods often has a certain underlying problem to resolve, a conflict. Schönberg has said that whenever a composer composes two notes there is a conflict between those two notes. The other part of the piece is to resolve this conflict in a way. This is of course not the only way to view music but it can help you to form an idea which 'conflict' or musical question you want to resolve through a particular piece (or the whole compositional path you set yourself on). This question can in turn give a lot of direction to which form you choose. Try to think this through in a fundamental way, you will learn a lot!