Key signatures

[creekster52]

Not one of Robert's lessons, none that I know of anyway, but I have always been puzzled by key signatures in standard musical notation. I realize most of us, as guitarists, never deal with standard notation, but I have always wondered how musicians develop an understanding of key signatures and how to instantly recognize the proper key of the piece. This is something I struggled with as far back as junior high school choral class.

 

[zagatron1]

About the only thing I remember about key signatures is they're a couple of symbols together on the staff. Y'know, like a sharp or a flat next to the clef. They designate notes that are to be played higher or lower than the corresponding natural note. Like a sharp symbol on a line or space in the key signature raises the note on that line or space one semitone above the natural and for a flat, below the natural. That's about all I remember 'cause I don't use that stuff. I'm surprised I remember that much. 

[robert]

If you know how to harmonize the major scale, it's not that hard.

C major, D minor, E minor, F major, G major, A minor, B half-diminished. Those are the chords when C major scale is harmonized.

If the progression is D minor, G major, C major, A minor, the answer is clear - it's in the key of C.

Another example, if the progression is F major, C major, A minor, G major - same key of C.

And so on.

Another hint will be the melody - you must always follow the melody. The melody will usually indicate which scale and key we are dealing with.

[creekster52]

Yeah...me too! I just never understood how to look at the sharps and flats in the key signature and instantly know the key of the song. Bearing in mind that my classes were choral, and no instrument involved to provide a visual association, I have to wonder if this may have been part of the confusion factor (and still is).

I would love to be one of those players who could walk in and play a song cold from sheet music. 

[robert]

The order of flats is the same as the order of sharps written backwards (F-C-G-D-A-E-B and B-E-A-D-G-C-F).  If anything, memorize one and re-write the order on paper backwards to figure out the other.

A mnemonic for sharps is:
Fat Cops Get Doughnuts After Every Bust

[robert]

Also see the circle of fifths.

I view it this way - one wholestep down from C is Bb, and it has 2 flats. Another wholestep from there is Ab, and it has 4 flats, Gb has 6 flats.

F has one flat, Eb has 3 flats, Db has 5 flats.

This also works up - D has 2 sharps, E has 4 sharps, F# has 6 sharps.

G has 1 sharp, A has 3 sharps, B has 5 sharps.

See the pattern? For each wholestep, you have twice the sharps/flats. Cool trick I learned a long time ago!

[creekster52]

I think it's time for me to go back to square one. It's been too long since I've done anything remotely related to theory.

[robert]

I view theory and reading music as 2 very different things. I am quite excellent in my knowledge of theory, but I suck so bad at reading music.

I don't ever need to read music, but I use theory all the time in my playing.

[hillbilly-joe]

Also see the circle of fifths.

I view it this way - one wholestep down from C is Bb, and it has 2 flats. Another wholestep from there is Ab, and it has 4 flats, Gb has 6 flats.

F has one flat, Eb has 3 flats, Db has 5 flats.

This also works up - D has 2 sharps, E has 4 sharps, F# has 6 sharps.

G has 1 sharp, A has 3 sharps, B has 5 sharps.

See the pattern? For each wholestep, you have twice the sharps/flats. Cool trick I learned a long time ago!

Thanks Robert.

[Vladan]

Robert's trick is really good, but involves some brains.

For us without it, find C on low E string, 8th fret
(That's because C scale is the base, nobs, no #, all white keys, 7 notes.)

Right below it, 5th string, 8th fret is F - one flat
Right below it is A#/ Bb - 2 flats
..... D#/ Eb - 3bs
For the second sring move to 9th fret, G#/ Ab - 4 flats
high E - C/ Db 5 flats

Now the oposite, high e 8th fret C

Above it G - 1#
G string move to 7th fret D - 2#
.... A - 3#
... E - 4#
... B - 5#

So, going downwards across the neck, in 4ths, gives bs.
Going upwards, in 5ths, gives #s.

If there was another one string, whichever way you went you'd come to F#/ Gb, 6#/ 6b, the middle of the road, a tritone from C.

Naturaly, being half step from C, both B and C#/Db can be written with 7b, or 7#, because all the notes are shifted half step from C major scale.
7b + 5# and 5b+7# give 12 semitones, whole octave,