Suggestions

I'm trying to understand how to write music. I can play most things within reason and I understand when a song is brilliant, but I don't know why. So I just wanted to see if anyone knows of a great, thorough music theory book. I would like to learn to write things of my own. I'm looking to understand things such as playing chords and then a fill to the next chord (as a way of playing rhythm and lead by myself) and also solos with chords (both sets of chords where you would play the same scale through the whole progression and chords that might require that you switch the scale on each chord). Also, I would like to understand some of the things I have seen James Taylor do. For instance, I have gone through some of his songs such as Carolina on My Mind and it seems like he never repeats a chord. I know he does but it seems like it's always a different voicing of the chord or a Em7 instead of an Em, etc. and it doesn't fit with a single key that I understand even within a single verse- it all sounds like one key with no obvious key changes to my ear but I don't know what key it would be. Or maybe it is just that I need to understand how chords other than minors or majors fit into a key like D/F#, etc. fit into various keys? I don't even know enough about these questions to know where to start looking, and the couple books that I have looked at seem both too much beginner and way too much advanced. Thanks so much for your help. it's greatly appreciated in advance.

I'm not sure what kind of music you listen to. I think one of the biggest benefits to me was leaning the blues. A book I would recomend is 'Blues you can use'. You will learn the theoary of the progressing (12 bar blues) and work to playing lead over a short 16 bar (usually) solo.

Another thing that helped me personally is deciding to put some music together. So I decided to write a tune in C major. I came up with a chord progression for the verse (C, Am, F, G) and a chorus (C, Am, Dm7, G). next i worked on some lead work.

I did not use a site as awesome as this. I mapped out the neck of the guitar, mapped out all the notes in C major and then mapped out some chords. I was proud of the result, though i still sound like a homeless drunk when i sing. Yup i wrote words to it as well. I learned a lot from the process.

Hope that helps

Well, if you want to know how to write a song it would help to view the songwriting category of this site, whereas if you want to know more about music theory then stay in the theory section.

Learn music theory and what modulating is. Learn how to modulate. Learn all the chords in each key. Learn how to construct scales. There is lots to know.

I've recently been checking out this site https://truefire.com. There are a couple of courses on song writing which might help you out also.