Musical "Keys"

[Fruitloop]

One of the cool things about the major scale (or the Ionian mode as it used to be called) is that there's one interval that only occurs once in each scale - the tritone between the fifth and the seventh degree. What this means is that you only have to hear this interval in order to know which key you're in. This interval forms half the notes in the dominant seventh chord, which is the chord that usually comes immediately before the tonic chord in the final cadence, providing you with a maximally unequivocal statement of the piece's overall key or tonality.

 

[beesonthewhatnow]

Teejay - Ok, so it seems that to spot which key a piece is in, is beyond the ability of all but the most accomplished music theorists?

I can do it within seconds for most stuff

 

[pooka]

Cor blimey, these amateurs !

eh?

 

[Fong]

eh?

I think he was mucking about pooka.

Does that mean that, given that there are only so many notes on the scale, there is a minimum number of notes you have to hear before being able to determine the key eg a simple melody line of say five notes might be in any one of a number of keys?

Yes, except in the case which Fruitloop highlighted, where a very peculiar Interval is. Which is specific to each Key.

However, if that 'jump' is not in the music, which it doesn't have to be, then yes you would have to hear a few notes before you could decide which key a piece was in.

Of course, an experienced musician can hear the Key based on the 'feel' of the music.

For instance, even tho I am entirely rubbish with music theory and have no perfect pitch at all, prefering to consider myself tone deaf.....I can still spot the A Minor Key a mile away, when listening and playing the guitar.

It has just been used soo often and has quite a distinctive sound that I have heard soo often.

I couldn't tell you any of the others, but that one I can spot.