Originally Posted by: btoby61

Hi all, been wrestling with the idea of tone centers and keys . Do they always align? which do I tie my solos to?[/quote]

There is a difference between functional & modal harmony. But they both share the same conceptual common denominators of chromaticism & basic music theory. The differences are in the application.

Originally Posted by: btoby61

Example: Sweet Home Alabama

Great example to use! :) I've seen that debated & argued endlessly on guitar forums. Some people really get worked up over it!

Short answer: It's in G major. But you could look at like it's a modal piece in D mixolydian (which is the 5th mode of G major).

[quote=btoby61]Starts on D Chord and seems to resolve there ...

So, how do I think about this? Key of G with a differnt tonal center being D and use D scales? Am I incorrectly assuming a functional harmony progression for this song and it is really a modal progression?

[p]You figure out what key a song is in by considering all the notes in all the chords & see if you can build a key signature (major or minor scale) from them.

I cover this in detail in this tutorial on improv.

https://www.guitartricks.com/tutorial.php?input=876

In this case it's simply a progression that starts on dominant & ends on tonic. More typical of classical or jazz, but not uncommon in rock.

D (V) - C (IV) - G (I)

The other big clue to listen for is the melody. What notes are being sung & played by the guitar leads. It's clearly G major with some bluesy minor 3 (B-flat) passing tones.

They do include an F major chord in there for a quick modulation, but it's also just to add more bluesy, swampy flavor to the G major sound.

You could think of it as being in D mixolydian. But that doesn't really help in this case because as soon as you figure out the melody notes & lead solos it's obvious that they are using G major pentatonic for 98% of the notes. The other 2% being that B-flat & F occasionally to make the lines more bluesy.

One final clue is that every live recording I've heard of Skynyrd playing it, they end on G. :)

Hope this helps!