What is a music key?
I think I worked it but I'm not completely sure. A key is made of notes from that scale so a song in the key of A major can only be played with notes and chords made from the notes of the A major scale so I can't play a chord like C minor because it has a C, Eb and a G while the A major scale doesn't have the last two notes.
- MordentLv 74 weeks agoFavourite answer
Broadly speaking, yes - C minor is not a chord in the key of A major.
Could you see it in a piece that's in A major? Sure - you just have to find a way of justifying the choice. C minor is actually a good way of introducing some colour and chromaticism - for instance you could have the chord sequence
Cm E/B A
All the notes in C minor can move chromatically to a note in E - C-B, Eb-E, G-G#
Could you just throw in a chord of C minor? Not really - it would sound quite jarring.
You could also see the notes of C minor as part of a larger chord - one of A half diminished (which has the notes A C Eb G, i.e the same as C minor but add in an A) which would work nicely at a cadence point.
A7(b5)/C B+/C Cm/Eb A/E E7 A
It really depends on how closely you want to look at a piece - does having one chord from outside the key mean you're not in the key any more? It depends on the context. Only having the home key notes/chords might quickly get very boring though.
- CharlesLv 54 weeks ago
With the use of natural, sharp, and flat signs, you can have any note regardless of what key you are in. A class in music theory would be beneficial.