Why no minor 5ths?

I get why there are no minor 4ths or minor octaves.

If you flat a 4th, you have a 3rd. If you flatten an 8th you get a 7th. Ok, makes sense.

No, you don't. If you flatten a major interval, you always get a minor interval. If you flatten a minor interval, or a perfect interval, you get a diminished interval. So, flattening a 4th would give you a diminished 4th - NEVER a third.
Flattening or sharpening will change the flavour of the interval, but never the interval, itself. A 4th is always a 4th, whether diminished, perfect or augmented. A 3rd is always a 3rd, whether diminished, minor, major or augmented.
But why are 5ths perfect?
Because inverting a perfect interval will still result in a perfect interval. Inverting a major 6th will give you a minor 3rd. Inverting a minor 3rd will give you a major 6th. Inverting a perfect 4th will give you a perfect 5th and inverting a perfect 5th will give a perfect 4th.
There's a whole step between a 4th and 5th right?

So why can't you flatten the 5th to make a minor 5th?

What am I missing here?

Nothing, really. It's just that there is no minor interval associated with perfect intervals, they become diminished, when flattened.
Major->minor->diminished
Perfect->diminished
Hope that helps.

I get why there are no minor 4ths or minor octaves.

If you flat a 4th, you have a 3rd. If you flatten an 8th you get a 7th. Ok, makes sense.

No, you don't. If you flatten a major interval, you always get a minor interval. If you flatten a minor interval, or a perfect interval, you get a diminished interval. So, flattening a 4th would give you a diminished 4th - NEVER a third.

Fb is E, E is a 3rd in C.

I'm afraid you've confused me here.

But why are 5ths perfect?
Because inverting a perfect interval will still result in a perfect interval. Inverting a major 6th will give you a minor 3rd. Inverting a minor 3rd will give you a major 6th. Inverting a perfect 4th will give you a perfect 5th and inverting a perfect 5th will give a perfect 4th.

I have no idea what you mean by "inverting a perfect interval." Can you explain what you're saying here?

Fb is E, E is a 3rd in C.
No, Fb is Fb. It may sound like E, because the two notes are enharmonic, but Fb is written on a staff as a note in the F line or space, but with a flat. The result is a diminished fourth above C (conversely, C-E# is an augmented third)

Inverting an interval means reversing the order of the notes. A perfect fourth, C-F, becomes a perfect fifth when it's written F-C. The thing that makes them perfect instead of major? Well, for a perfect interval, each note is naturally in the key of the other note... F is in the key of C, and C is in the key of F.

If the higher note is in the key of the lower, but not the other way around, the interval will be major... so C-E is a major third; it's not perfect, because althouth E is in the key of C, C is not in the key of E - in the key of E, it would be C#.

So just becuause two things are the same doesn't mean they are the same! Don't you just love music theory :D

Context is everything.

There was a young lass from Elsass
who had a magnificent ass.
Not rounded and pink
as you probably think,
It was gray, had long ears and ate grass.

I see that the second line was changed by the languagebot.

You get my point though?

Yes I know context is important. But it is still confusing at first!

It's like language in that the name thing can mean a number of different things. "light" being such a word.

Polish polish

Buffalo buffalo buffalo buffalo.

Yes, that's a proper english sentence.

On a more serious note, thanks for the explaination about perfects and inversion. I get that and it makes sense.

I'm afraid I just don't get the enharmonic thing ... maybe 'cause I'm looking at it from the perspective of the tones and not the perspective of the staff?

I just look at it and say hmmm 324Hz (or whatever Fb is) is 324Hz (or whatever E is) it doesn't just sound the same, it is the exact same tone, played on the same fret on the same string, on the same guitar, over the same amp... there's NOTHING different about it. So saying it's NOT a 3rd it's really a diminished 4th just makes me scratch my head.

In a major scale on a modern guitar a 3rd IS a diminished 4th. It is the same exact physical phenomenon. They just don't sound the same, they are the same.

It seems to me that it's sort of like photons. You can look at it as either a partical or a wave, for the purpose of a particular model, but in reality it's both/and not either/or.

I think thinking about it like language is better.

I doesn't nessecarily make physical sense.

Do you have a light?
Does that feel light?

The word 'light' is exactly the same in each sentence. But has a different meaning. Or you could think of it like a optical illusion: http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html

I don't think wave-particle duality is a good analogy as it's not a physcial property. It's due to how the human brain works. Like, in that optical illusion you think they are different when physically they are the same. There's no explanation other than human perception...

Think of the enharmonic names more in the vein of solid water and ice. They are the same thing, but solid water conjures up a different image in the mind to ice - it relates more to an altered state of water than a state of it's own (ice)

how about: they are synonymes for each other but cannot be exchanged every time depending in which situation they are used.

btw: what's Buffalo buffalo buffalo buffalo supposed to mean.

Sorry if this sounds a bit ridiculous, but it's rather late here and I had a looooooong day....

:oops:

good night

how about: they are synonymes for each other but cannot be exchanged every time depending in which situation they are used.

btw: what's Buffalo buffalo buffalo buffalo supposed to mean.

Sorry if this sounds a bit ridiculous, but it's rather late here and I had a looooooong day....

:oops:

good night

:lol:

I think it's better to call them homophones: two 'words' that sound the same but are spelled differently and have different meanings.

You-ewe.
No-know.
One-won.

etc.

[/geek] :shock:

Bison from the city of Buffalo fool bison.

WTF? I've never in my life heard of a diminished 4th. WTF?