Chords used in a key?

Hi Guys,

Please can someone clear this up for me. I've spent months playing around with progressions from this chart...

http://www.ezfolk.com/uke/Tutorials/1four5/music-theory/key-chord-chart/3-key-chord-chart.jpg

But when I check tabs online (now I know they are not fully accurate) there's still many chords that are not in the key chart being used. Why is this? Why do I see the Key of A being A, Bm, C#m, D, E, F#m, G#dim but I see a song that starts with A chord and most chords are being used from the chart but I see chords like G. Why can we use G if it's not in the key?

When can I use chords that are not in this chart? Am I wrong and using this chart and shouldnt bother at all? or can I add chords when ever as long as it's using the same sort of chords from that key?! I'm so lost and any advice would be great :)

you can use what ever chords you want in any musical piece. most musitions do. what sounds good matters more than what is set in music theory.

Thanks for the reply. but is it good to have a key to structure your songs but then add the chords in or is it all goes wherever you want?

It is always good to have some sort of structure. You should check these lessons out:

Music Theory: A Look Down the Path of...

Scales and Their Chords

Harmony Using Chords

Music Theory - Turning Your Scales into Chords

Those should help!

Rock on!

it good to start out on your own making songs with only the chords of the key, and learning other peoples songs that don't stay and/or follow in the one key. Then start to experiment on your own with different progression you have experienced. Thus you'll get an ear for what going. Developing an ear is very important (don't think perfect think relative). So yes learn the chart very important for theory.

but to answer your question, many songs don't stay in one key. Many songs used accidentals (notes outside the key) and then build chords off the accidentals. Many use different progression from other keys and used that theory on why it works over another key.

An example and the first one you should learn is secondary dominates. You take the theory of a Dominate chord resolution to the root chords of the Ionian mode and apply it to others that don't have it. For example Ionian In Key of C would by G7 and Cmaj. But lets use that idea in A Aeolian. The 5th would be an E chord but in Aeolian it's a minor not a Dominate. So we just sharpen the third and get a E7 to A minor. Thus the secondary dominate in A aeolian is E7.


I don't expect you to get any of that and it is a gross simplification, but I like to give people a heads up on where they can be going. My point, is don't give up and learn the basics and experiment with different songs (always always learn new songs) your on the right track. Hopefully my post is just a look forward and one of many directions you can head in music theory. I just always like a light in the distances I can head towards, instead of wandering in the dark.

Thank you so much guys. these answers really help :)