3rd FFcP Fourths Exercise (theory question)

[wormpicker]

Hi everyone. I’m a newbie, about 9 months into this mandolin journey. I have a question about the “fourths” exercise in the 3rd FFcP “Ionian Mandology” set from Getting Into Jazz Mandolin.

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I scribbled a red line between the note and tab position in question. This exercise is in the key of C. I understand that in a C scale, the 4th note counting from F is a B. But this interval doesn’t “sound” like my understanding of how a 4th interval sounds (e.g., like the first two notes in “HERE COMES the bride”). To me, the properly sounding 4th interval would be F to Bb. Of course, Bb isn’t in the C scale (but is in the F scale). So, how does this work? Is a 4th from F in the Key of F a Bb, but a 4th from F in the key of C a B natural?

[wormpicker]

Hmm, I think I found the answer to my question (https://en.m.wikipedia.org/wiki/Perfect_fourth). F to B is a fourth because it spans 4 staff positions, but instead of being a perfect 4th (5 semitones), it’s a diminished 4th (4 semitones)?

How does this relate to playing music? Is this one of those “cerebral jazz theory” that the book says it would spare me? The more I learn about music theory, it seems, the less I understand it.

[Mark Gunter]

There are actually three different fourth intervals, not just one.

The fourth you're thinking of is the Perfect Fourth. A perfect fourth consists of five semitones, or half-steps.
Four semitones is the interval of a major third, but also of the Diminished Fourth.
Six semitones is the interval of the Augmented Fourth (also, the diminished fifth, aka the "tritone" interval).
I suppose the reason he moves to the augmented fourth is to stay in the C scale, as you've surmised.
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I see you found 'an answer' before I got the post submitted. (I stopped for 10 minutes to play the scale you posted). You're on the right track, but it's actually 6 semitones between the F and the B, so it is an augmented fourth, not a diminished one.

[wormpicker]

Thanks Mark. Ah, you’re right. I mis-counted. F to B is 6 semitones—augmented 4th.
This stuff is complicated.

[Mark Gunter]

Here's a chart that might help you with intervals:

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[Mark Gunter]

It does seem complicated, but it's really not too complicated. For me, this stuff is learned over time, not all at once. For me, the process went something like this, over a period of years:

1. Learn the definition of a major scale.
2. Name the intervals of the major scale (major & perfect intervals).
3. Learn that reducing a major interval by 1/2 step makes a minor interval.
4. Learn that reducing a minor interval or a perfect interval by 1/2 step makes a diminished interval.
5. Learn that increasing a major interval or perfect interval by 1/2 step makes an augmented interval.
6. Memorize just how many semitones (1/2 steps or frets) define these intervals.

I'm still working on #6

[MandoAblyss]

You are on course, and it will make more sense the more you use it. Might help to distinguish scale degrees from the quality of the scale degree. To make a 7-note scale of course you must use every scale letter at least but no more than once. So in any kind of C scale--of which there are many--the third scale degree will always be some flavor of E. In notation, there is a full space between them. Counting intervals, you name where you start so C-D-E is one-two-three: E is the third.

But there is more. In C major, the E is a natural E and the interval from C is a major third--two whole steps. In C minor, the "E" is Eb and the interval is a minor third--one-and-a-half whole steps (or three half steps). Since there is a full space between the two dots in both cases, how do you know whether it is a minor, major (or even augmented) interval? You must look at the key signature and any accidentals next to the notes.

I guess one way to think of it is THE INTERVAL--third, fourth, whatever. Just the plain letter. And then second, the quality of the interval--diminished, minor, major, perfect, augmented, whatever.

It may be convention to label THE INTERVAL with a number. You will often see this in expressing chords: 1-3-5-7. Literally, this would be a major 7 chord. Now a minor 7 flat 5 chord also uses "1-3-5-7" INTERVALs from the scale, but the notes (related to a major scale) are 1-b3-b5-b7. These notes are diatonic to a major key only if you are playing the 7 chord corresponding to the 7th scale degree (a Bmin7b5 in key of C). In other words, in the key of B (major) the diatonic 7 chord (or I chord) is B-D#-F#-A#. But in the key of C the diatonic B chord is B-D-F-A, or a minor 7 flat 5.

In your example, all the notes you play are diatonic (of the scale) to the key you are in, C. So when you play fourths, you just count up four letters within the key. These won't all be perfect fourths because of the way the major scale is constructed (W-W-H-W-W-W-H steps); in fact they ARE all perfect fourths (five half-steps) except from the 4th (F) to the 7th (B) scale degree which is an augmented fourth, also known as the tritone, (six half-steps/3 whole steps, splits the scale into two equal parts, found directly opposite on the circle of 5ths) and a crucial interval in defining the sound of any given scale. So you have a good ear, the tritone does sound very different from a perfect fourth.

IF you were playing this exercise in the key of F, the fourth above F you would play was Bb--diatonic to F major--and it would be and sound like a perfect fourth. But then when you got to the fourth scale degree of F major, Bb, the diatonic fourth above that would be E, an augmented fourth or tritone, and it could sound odd just as the F--B in key of C.

If you play diatonic chord scales, the chords corresponding to C major are Cmaj7, Dmin7, Emin7, Fmaj7, G7, Amin7, Bmin7b5. They will sound "right" when you play them in order, but also wrong because the minor chords have different tonality from major from dominant from half-diminished.

Now you are headed for modes, blues and jazz. It is a fantastic journey!

As you use this stuff more, you will intuitively understand the context and the meaning of fourth vs. fourth will become clear. There is an excellent book called String Theory, Music Theory Fundamentals for All Mandolin Players by Ray Chesna (also a guitar version)--well-written, thorough and fun with exercises along the way. It will give you a complete understanding of scales, intervals, inverted intervals, triads, 7 chords, and chord tensions. Unfortunately, it does not seem to be available on Amazon or Ray's website. Perhaps worth contacting him about it--by far the best mandolin theory book I've seen and I have many!

[wormpicker]

Wow, thanks so much for this thorough explanation! I’m going to have to re-read it a few times, with my mandolin in hand, to fully digest everything, but this is really helpful. Thanks also for the book recommendation. I’ll look for the book.

[billhay4]

I'm not finding this book anywhere. Any help appreciated.
Bill

[Mark Gunter]

I'm not finding this book anywhere. Any help appreciated.
Bill

A little pricey: http://raychesna.com/product/music-theory-fundamentals-for-all-mandolin-players-book/