Difference between scale an key?

[YoungCapone]

Originally, I thought that key and scale were essentially the same thing. I thought "key" was just a way of saying that (for the most part) we will be using notes from a certain scale. Maybe, C major, maybe B minor etc… But, the more I’ve studied theory there seems to be a deeper, more fundamental difference between the two.

For example, apparently you can use multiple scales within one key. I don’t understand why the key of C major would be called C major if you can use notes from other scales… My first thought would be that multiple scales can use the same notes, which makes sense. But, then my next question would be, can you use notes outside of the C major scale in the key of c major?

I've also heard “it all has to do with the concept of tonality”. I have a vague understanding of tonality, so how specifically does tonality determine what can be played or should be played within a certain key?

I feel like if I've learned anything in music theory it's that there are a lot of rules, but even more exceptions to the rules. Just saying that so you know I get that your answer probably won’t be as cut and dry as I'm asking haha

 

[rhythmgj]

Exactly. Music theory just describes a general set of extrapolated principles based on what sounds good and certain historical cultural practices.

For our purposes, Key and Scale are, *almost* the same thing. Key really describes the tonal center (where does everything want to “come home” to). But you can be flexible within that, because as Joe Meek said— “If it sounds good, it *is* good.”

GJ

 

[Stereogram]

I always considered the terms interchangeable but if there was a difference it would be that a scale is specifically the playing of an ascending or descending sequence of notes within a certain key.

 

[rhythmgj]

See?^^^^ That is actually a perfectly concise and correct answer. *Within* that key, other scales and modes related to it can be used, but the basic underlying harmony and harmonic relationships will be based on that key’s major scale and its degrees.

Don’t get too hung up on it. It’s an organizational framework for music. But yes, other notes than those in the major scale can work over chords in that particular key. And that’s fine...


GJ