Circle of Fifths - what's the purpose in knowing sharps and flats?

[Eskimo_Joe]

I've been learning the circle of fifths and understand it is useful in understanding relationships and useful as a practice tool, but why is it useful/important to know how many sharps/flats there are in a given key?

 

[Kappy]

Mostly for reading and writing, but also for just knowing what notes belong to what key when you're analyzing music. Arbitrary example: you're transcribing a melody in the key of E and you encounter a G natural, knowing that it's not part of the E major scale (4 sharps, FCGD) gives you a pointer about why it's being played (and where it might come from).

 

[Jamie_Mitchell]

If you just ignore the sharps and flats part of it, you'll see a couple things I find very useful/enlightening;
A lydian scale starting on C covering half of the circle, moving left (becoming less resolved) til it reaches Phrygian.
C literally in the center of F and G, balanced between them as tonic.
Chordal resolution to the left, look at a ii-V-I as a clear harmonic move in the circle, same with iii-vi-ii-V-I.

There are probably many others, this is just what comes to mind as very helpful to me.
Jamie

 

[Swain]

Well, in reading music there is something called a Key Signature. With this, you can alleviate a lot of extra "clutter" on a Transcription. This makes it easier to read.
If I see 1 # at the beginning of a piece, it's probably going to be on the top Line of the Staff. This means it represents an F#. So, this probably means the Key of G.
With this information, you can immediately narrow down your efforts for a more productive result.

 

[kimock]

If you just ignore the sharps and flats part of it, you'll see a couple things I find very useful/enlightening;
A lydian scale starting on C covering half of the circle, moving left (becoming less resolved) til it reaches Phrygian.
C literally in the center of F and G, balanced between them as tonic.
Chordal resolution to the left, look at a ii-V-I as a clear harmonic move in the circle, same with iii-vi-ii-V-I.

There are probably many others, this is just what comes to mind as very helpful to me.
Jamie

Sure, in Greek!
Look at it like this, it's like a PIN, you don't get the PIN, you don't get in.
Or maybe you do, but eventually somebody's gonna catch you and ask you for the PIN, and you're not going to have it and you'll have to call a friend.
That's pretty much it . . .

 

[JonR]

I've been learning the circle of fifths and understand it is useful in understanding relationships and useful as a practice tool, but why is it useful/important to know how many sharps/flats there are in a given key?

What's useful is knowing what notes there in a given key. The actual number of sharps/flats is irrelevant (ie, that depends on the notes, not vice versa).

However the circle of 5ths is one of those patterns that keeps cropping up - it has a musical meaning (unlike a lot of other patterns you learn on guitar).
Eg, it's not just a handy diagram of keys (adding or subtracting a sharp or flat in each direction). It can be used to pick groups of chords that work well together - if you have a circle that includes the relative minors on the inside, like this:

The main 6 chords in any one key are grouped in a block of six (a quarter sector of the circle).
The tonic (I) is in the centre outside, the IV is on the anti-clockwise side and the V is clockwise. Inside those 3 are the minor chords in the key (ii, vi and iii, in that order clockwise).
Naturally all these 6 work well together.
Eg, the key of A major includes the chords D (IV), E(V), Bm (ii), F#m (vi) and C#m (iii). (Yes, the vii chord is missing, but who needs that anyway? )
Moreover, you can add to this set by looking at chords another step away on the circle - they will sound a little "out" but will have useful functions - such as (for key of A), G or B major.
The further apart on the circle any 2 chords are, the less related they will sound. This is useful to know, because sometimes you want a surprising chord, and you can always find one on the other side of the circle.
(And there are more useful links if you think parallel minor - for more chords to add to key of A - to sound "out" but still in a quirkily related way - try those gathered around the Am chord...)

 

[KRosser]

It's the fundamental vocabulary of western music.

What that should mean to you only you can say, but I can tell you what that meant to me: I had to know it.

 

[rob2001]

So you can play Love me two Times by the Doors?

 

[Doc W]

If you play mainly by ear, you don't need to know any of this. However, if you want to play in a given key, particularly if you want to improvise, you need to know the scale and thus sharps and flats are crucial (as long as you also know the fretboard).

At a more basic level, it will help you to understand chord relationships and change key easily. For example, you are playing a song with the chord sequence C Am Dm G7 and you want to play it in E. It becomes E C#m F#m B7. If you don't know scales (and sharps and flats), it is a little more difficult to figure out.

But don't make it into a burden. It is better know how to figure out how many sharps are in a key than to mindlessly memorize each one (ask if you don't know how). After playing in different keys for a while and paying attention to the fretboard, you will remember key signatures. It takes a while but it will get really easy.

 

[jaydub69]

The further apart on the circle any 2 chords are, the less related they will sound.

Jon, I see on your chart that the opposite end of say "C" is F#/Gb.
I can hear these chords as being discordant, and yet... If I play a C dominant and want the Tritone sub (flat 5)...bingo- a Gb .
I realize that C7 (or C7b5b9?) is in the KEY of F, yet it is still "further" (on the chart) from the root than the IV, V, II or VI.

So what does "less related" imply? Am I confusing the two approaches?

-john

 

[bigdaddy]

I don't play on stage a lot but I do see this every now and then at jams. The '1 up' or '2 down' signals/terminology to indicate keys for a jam. Is this still in practice?

 

[kimock]

Jon, I see on your chart that the opposite end of say "C" is F#/Gb.
I can hear these chords as being discordant, and yet... If I play a C dominant and want the Tritone sub (flat 5)...bingo- a Gb .
I realize that C7 (or C7b5b9?) is in the KEY of F, yet it is still "further" (on the chart) from the root than the IV, V, II or VI.

So what does "less related" imply? Am I confusing the two approaches?

-john

If I understand the question correctly, you're confusing "related" as in related at all with "close harmonic relationship of triads" which I believe was JonR's point.

The 'pie chart, relative minor' view of the circle isn't the easiest way to visualize the chords in a key for me. The lines are actually connecting the quarter tones between the letter names. Use a standard circle with the letters on the outside, and just connect the tri-tone line for the key.

So for C draw a line between F and B. Everything in the "key of C" including the vii chord will fall between F and B on the clockwise side of the line. Everything on the other side of the line is not in the key.

Now if you look at the Dominant 7 chord on that clean circle, you see F and G on either side of C. The resolution to C would be the F and G collapsing toward the center.

With the altered chord you still have that diatonic tri-tone line between F and B, but you've added a tri-tone line between G and Db/C#.
So the collapse toward the center resolution routine can be happening in either C or F#.

So relative to key in a conventional sense, while it may be true and correct to say that you're using that tri-tone sub in a key, the chord itself isn't exclusive to one key because of the two crossed tri-tone lines.
At least not in the same way that the diatonic harmony is exclusively generated by those pitches falling on only one side of one tri-tone line.

So you can have close harmonic relationships that cut across that tri-tone line, inversions or reflections or symmetries, that may or may not be "in a key" from the perspective of diatonic harmony. Sometimes you use 7 notes, sometimes all twelve.

Apologies in advance for putting words in JonR's mouth. . .

 

[Clifford-D]

If I understand the question correctly, you're confusing "related" as in related at all with "close harmonic relationship of triads" which I believe was JonR's point.

The 'pie chart, relative minor' view of the circle isn't the easiest way to visualize the chords in a key for me. The lines are actually connecting the quarter tones between the letter names. Use a standard circle with the letters on the outside, and just connect the tri-tone line for the key.

So for C draw a line between F and B. Everything in the "key of C" including the vii chord will fall between F and B on the clockwise side of the line. Everything on the other side of the line is not in the key. .

This puts the "modes" or chords of the key of C in an order from bright to dark - Fmaj7 Cmaj7 G7 Dm7 Am7 Em7 Bm7b5

Now if you look at the Dominant 7 chord on that clean circle, you see F and G on either side of C. The resolution to C would be the F and G collapsing toward the center..

Fmaj7 > C < G7
Dm7 > Am < Em7

With the altered chord you still have that diatonic tri-tone line between F and B, but you've added a tri-tone line between G and Db/C#.
So the collapse toward the center resolution routine can be happening in either C or F#..

confused here, is this like a modulation? or are you just pointing out the bi-key relationship? I think the latter.

So relative to key in a conventional sense, while it may be true and correct to say that you're using that tri-tone sub in a key, the chord itself isn't exclusive to one key because of the two crossed tri-tone lines.
At least not in the same way that the diatonic harmony is exclusively generated by those pitches falling on only one side of one tri-tone line..

that answers my question pretty good.

So you can have close harmonic relationships that cut across that tri-tone line, inversions or reflections or symmetries, that may or may not be "in a key" from the perspective of diatonic harmony. Sometimes you use 7 notes, sometimes all twelve..

C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>??

Apologies in advance for putting words in JonR's mouth. . .

 

[kimock]

C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>C>Ab>E>??

All 12, sure. So not diatonically close, and you're not gonna get any farther cutting everything into equal bits without stepping on your tail.

Still a basic symmetrical division of the circle though, right?

 

[JonR]

Jon, I see on your chart that the opposite end of say "C" is F#/Gb.
I can hear these chords as being discordant, and yet... If I play a C dominant and want the Tritone sub (flat 5)...bingo- a Gb .
I realize that C7 (or C7b5b9?) is in the KEY of F, yet it is still "further" (on the chart) from the root than the IV, V, II or VI.

So what does "less related" imply? Am I confusing the two approaches?

-john

You've pointed out the interesting opposite relationship, which depends on the tritone. The tritone is of course the most tense interval (in terms of functional meaning, as opposed to plain dissonance) - it has a kind of balanced tension. C7 and Gb7 share their internal tritone (E-Bb = Fb-Bb) which is why one can stand for the other functionally. Each can resolve to either F or B (or Fm or Bm).

Steve has pointed out other aspects of the tritone and the effects of that "equal-but-opposite" symmetry.

The "Coltrane changes" major 3rd cycle (that Clifford refers to) can also be visualised easily with the circle of 5ths.

There are many of these pattern "games" you can play with the circle, but the appeal is that most of them have musical meaning and value.

 

[Clifford-D]

You've pointed out the interesting opposite relationship, which depends on the tritone. The tritone is of course the most tense interval (in terms of functional meaning, as opposed to plain dissonance) - it has a kind of balanced tension. C7 and Gb7 share their internal tritone (E-Bb = Fb-Bb) which is why one can stand for the other functionally. Each can resolve to either F or B (or Fm or Bm).

Steve has pointed out other aspects of the tritone and the effects of that "equal-but-opposite" symmetry.

The "Coltrane changes" major 3rd cycle (that Clifford refers to) can also be visualised easily with the circle of 5ths.

There are many of these pattern "games" you can play with the circle, but the appeal is that most of them have musical meaning and value.

Diatonic;

Circle (cycle) of 5/4

Cycle of 3/6

Cycle of 2/7


Symetrical, inverse, "reciprocal";

cycle of b3/b3/b3/b3

cycle of maj3/maj3/maj3

cycle of #4/#4


All have purpose.
(I know I'm leaving out all the important intonation stuff, keeping it simple )