Fingering a Fifth
You probably know it as a “1 by 2”: one string up, two frets over, like this (the numbers are fingering options for fifths):
The Forgotten Fifth
But what about this one:
Across two strings you get your fifth covered between the pinky and the first finger. Totally one-finger-per-fret! And totally useful, especially for triads.
Check this out:
When you play a 5th below the root you are actually playing the interval of a 4th.
That is because…
Fifths and fourths are inversions of each other.
I am sure you have done this: played a 1 – 5 groove with the 5th below the root. So you’d play C (let’s say that’s what the chord is) and the G (the 5th scale degree of C) below that C. Technically speaking the interval you just played is a 4th, however. Fourths and fifths are inversions of each other: in music 4 + 5 = 8 (inversions add up to the octave, which is 8)
Watch the CG ascending form a fifth, while the CG descending forms a fourth:
Yes, you are playing the fifth scale degree if you go down to that G, but the interval you are playing is that of a fourth descending. If you were to play a fifth descending from the C, you’d end up at the F below.
It is correct to say you are “playing the fifth below” (meaning the G, which is the fifth scale degree of C major), but be aware that the interval you are playing is that of a fourth (so you are “playing a fourth down”. Sounds close when you say it in words, but to understand the difference is important.
Another way to think of it:
C is the root. G is the 5th. Where you play that G doesn’t matter. You can play it a 5th above or a 4th below that C. A bit of a different effect, but!
More on the fifth to come! Stay tuned!