Part 8 – What Else?

I'd like to help but that question is a bit too vague. Can you please explain what you mean by "understand the scale of a song"?

Perhaps I'm thinking "How to tell what key a song is in?" is what you are asking.

Well there's several ways to do that. But it's too much to write here. However, it's probably worthy of an article sometime.

But generally, you can usually take the last chord of a song (and sometimes the first) and that will be the key.

Then there's your 'experience' of knowing what the home chord is for a song, too. But you need ears for that. So I hope you are working on ear-training.

Then there's the old 'analyze the chords' method. That's where you look for signs of what they key may be…

… for example – if the song has 2 major chords a whole step apart then it's a reasonable safe bet the chords are the IV and V chords because they are the only MAJOR chords that are a whole step apart.

So if your song has a C chord and a D chord, then your first guess for the key will be G major. Or it's relative minor – Eminor.

But then, some songs change keys during the song, and some even end in a different key from where they started.

Hope that helps a little.

What do you mean by 'understand' the key of a song? Your question is too vague, sorry.

Well, you could voice chords in 4ths, or use triads for an example. Clusters usually refer to chords with voicings close together such as maj2nds. Bit of a deep subject to explain fully here. There a great book by Bret Willmott called "Complete Book of Harmonic Extensions for Guitar" that you may find interesting if you want to go deep.