A question about intervals.

If you are moving down in pitch do the intervals stay true? I mean, a lower C to a higher G is a perfect fifth, but what about moving from a higher G to a lower C? Would that be a fifth or a fourth?

If you are moving down in pitch do the intervals stay true? I mean, a lower C to a higher G is a perfect fifth, but what about moving from a higher G to a lower C? Would that be a fifth or a fourth?

the interval is not determined by the movement of a voice, but simply by the number of steps between two notes.

C to the G above is a 5th, whether the notes be played simultaneously, the C first, or the G first.

If you want an exaggerated example to demonstrate this (since you mention the 5th/4th relationship):

go from C up to D... you have a second.

logically, is then going from that D back down to C a 7th? (the 7th being the inversion of the 2nd)

it sounds kind of silly, but it's basically the same thing.

the number of steps you move from one note to the next is what determines the interval. C up to G is a 5th. G down to C is a 5th. The same number of steps have been covered.

On the other hand, C down to G is not a 5th. In this case, you have the inversion of the original interval, or a 4th, if you prefer.

If you know maths, you can think of it as vectors, with the magnitude being the interval, and the direction being "up" or "down": if you take a vector from C to G, it has magnitude 5 notes of the C major scale (7 semitones), so it is a fifth. If you take the same vector and inverse it, so that it goes from G to C, the direction is different (G is played first, and C second), but the magnitude is the same, it doesn't change.

But I think Qccowboy explained it pretty well, so now that I showed off my super-duper-extra-intelligent-vast knowledge of maths (...NOT...), I'm off to read some other threads which I can actually contribute to... :)

But I think Qccowboy explained it pretty well, so now that I showed off my super-duper-extra-intelligent-vast knowledge of maths (...NOT...), I'm off to read some other threads which I can actually contribute to... :P

OUCH!

:)

Thank you for clarifying, but I have yet another question. If a C and a G are played at the same time. Is that a fourth or a fifth? Because a G to C is a fourth, but a C to G is a fifth.

Thank you for clarifying, but I have yet another question. If a C and a G are played at the same time. Is that a fourth or a fifth? Because a G to C is a fourth, but a C to G is a fifth.

exactly the same thing I wrote in my post.. reread it.

if the C is below, and the G is above, no matter if the notes are played one after another, in reverse order or simultaneously... the interval is unchanged.

Here's a trick...

Always measure an interval from the lowest note up, even if it comes second in the pair you want to analyze.

Intervals are aways measured as an absolute from the lowest note of a pair to the highest note of a pair, regardless of the order of performance.

let me give you a VERY extreme example..

the lowest note on a piano is an A.

the very highest note on the same piano is a C.

the interval from A to C is a minor third.

It is STILL a minor third, even with 7 octaves between them.

Thank you I get it now. I didn't understand that it was the lowest note that determined the interval, I still thought it had to do with which one was played first. I should have read your first post more carefully.

Let me complicate things a little. Depending on the harmony and the intentions of the composer, you might have different intervalic relations for the...same interval. For example, A - C (the keys on the piano) might as well refer to A - B# (an augmented second) in a specific harmonic setting. Confusing, huh?

Yeah, enharmonics can be pretty crazy at first, but they're not that hard to understand after a bit of study.

Now for Monkey: Its not the lowest note that determines the interval, but the relation between them. A "C" up to a "G" is a prefect 5th. A "G" down to a "C" is also a perfect 5th just in the other direction. It only becomes a 4th when it is inverted, or when "G" goes up to "C" or "C" goes down to "G".

Thank you I get it now. I didn't understand that it was the lowest note that determined the interval, I still thought it had to do with which one was played first. I should have read your first post more carefully.

If you want, you can go to the "Lessons" section of the forum. I have posted a couple of lessons there for other members dealing with intervals and inversions. Although, it seems you understand the concept now. But, it might help all the more. :toothygrin: