I have some basic knowledge on chords but I was wondering what books on chords and theory were the best for expanding my musical knowledge? As in, intermediate to advanced level books ?
It depends. I wouldn't use the Kostka and Payne if you're just wanting to learn about chords, structures, and basic voice leading. You're not very specific in your question. Do you want to learn more about theory the way Reina is describing, or something more contemporary? I would recommend the following books:
The Everything Music Theory Book - Marc Schonbrun
Those are two good ones to start with. There's a really good free book offered by some conservatory that I found online a while back. Check here:
It's long, but quite good for fundamentals, and even includes some jazz and blues theory as well. You can't print the book out, but you can download the PDF. So if you have an iPad or some other tablet, it's great to have on the go!
Hope that helps!
These are online rather than books, but have the added value that you can hear the output or link directly to video:
The book I used through college, and still use quite often now, is Tonal Harmony by Kostka and Payne. The current edition is quite pricey. But I picked up an old edition a few years ago for just a couple of bucks. Theory doesn't really change, so go with the old edition.
What's great about that text is that it goes sequentially through all of tonal harmony and theory: naming chords, chord progressions, structural analysis, and even gets into 20th century theory.
There's an accompanying workbook, but the text has practice sets and analyses at the end of each chapter that are great.
If you want to learn about music theory, chords, chord progressions, and chord viocings in jazz music, and related genres, I believe that 'The Jazz Theory Book' by Mark Levine is one of the best and most comprehensive. It guides you from the basics all the way through to the most advanced. It could keep you busy for years.
Good luck on your endevour!