#1
I'm happily struggling to write my first jazz tune, having little to no musical theory whatsoever.

Emaj7, Am9 Am7, Emaj7, Am9 Am7, C#9, F#m, B9
Emaj7, Am9 Am7, Emaj7, Am9 Am7, ***E9, Am7

Okay, so I didn't bother to convey timing, so shoot me.

On the second line, I want to go to E9 and then back to Am7 but it seems like that little piece is in key of C.

As I said, I know nothing about theory, so maybe my whole song isn't even in a key...Maybe I'm just coming up with an immature out-of-key chord progression...

Advice?
"Calling her a ***** for lame shows isn't exactly the most romantic thing in the world. Seriously buddy, try not to be so cute and funny, and just try to be romantic, because this is garbage.
I'd probably take a small amount of offense to this if I cared about being Jewish, but I don't.

Good intentions yeah, but expect either your heart to broken, or a slap in the face, because this song will end in disaster."
#3
Okay, so I take it it is acceptable to change keys in a song.

Then how do I get back to the original key (when I start off with an Emaj7) from, for example, the E9 then Am7 chord. What kind of turnaround could I use?
"Calling her a ***** for lame shows isn't exactly the most romantic thing in the world. Seriously buddy, try not to be so cute and funny, and just try to be romantic, because this is garbage.
I'd probably take a small amount of offense to this if I cared about being Jewish, but I don't.

Good intentions yeah, but expect either your heart to broken, or a slap in the face, because this song will end in disaster."
#4
course you can change key. i mean this in the nicest way possible: you can't do jazz if you dont know theory.
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#5
here's a definitive way to tell if something you're composing is "right."

ask yourself: does this sound good to me?

if the answer is yes, then you're playing it right.

if the answer is no, then you're playing it wrong

end of story. all music that sounds good to the ear can be explained using music theory, and if something seems bizarre, it may be what i like to call a "tasteful stretching of the rules"
#6
LOL, points duly noted.

How could I turnaround from Am to to Emaj7???
"Calling her a ***** for lame shows isn't exactly the most romantic thing in the world. Seriously buddy, try not to be so cute and funny, and just try to be romantic, because this is garbage.
I'd probably take a small amount of offense to this if I cared about being Jewish, but I don't.

Good intentions yeah, but expect either your heart to broken, or a slap in the face, because this song will end in disaster."
#7
Changing keys in a song is called Modulation. you modulate from one key to another.
Not only is it acceptable it's quite common