I feel stupid, but... what is an octave?

[Bricolo]

I always hear (read ) about octaves, what do they correspond, technically?

same question for decades )


thanks!

[SY]

A factor of 2 in frequency. 100 Hz is an octave below 200 Hz. 200 Hz is an octave below 400 Hz.

[faustian bargin]

you can hear this relationship with a string. half length = 1 octave higher. some old greek guys did some experiments.

/andrew - it's all greek to me anyway

[Bricolo]

since you're talking me about string lenghts

yesterday, a friend who's playing guitar, told me that every 6 strings of a guitar are playing the same frequency, and I didn't believe him

when I thibk about it, it's quite logical since they have the same lenght
but what's the purpose for 6 strings, so?
they haven't the same diameter, so not the same mass, this certainly change theyr resonance frequency

[Won]

I think that your friend is wrong.

The strings have different masses and different tensions. When you tune the guitar you adjust the tension on each individual string to get the appropriate note. Different frequencies are different notes (this is where the term octave comes from, I believe).

-Won

[Bricolo]

can each string be an octave higher than the other?

[faustian bargin]

sure, why not?

although you're going to end up with some mighty tight strings...or mighty loose on the low end. you'd probably have to use special strings to achieve safe playability.

/andrew - says "no string violence" (violins?)

[SY]

It CAN be, but with standard tuning, it's not. In the case of 6 string guitars, each string is tuned 5 half-steps above the next lowest string (except the B string, which is 4 half steps below the G string). 12 half steps make an octave, BTW.

With violins, the tuning is 7 half-steps between strings, IIRC.

And 12 string guitars have four of their strings paired with smaller strings tuned an octave above.

[stefanobilliani]

A normal set of chords for guitar starts from the note E at 82.41 hz
then :
note A at 110.00 Hz,
note D at 146.83 Hz,
note G at 196.00 Hz,
note B at 246.94 Hz.
note E at 329.63 Hz.

The second note E in the list is at 329.63Hz , 4 times the first E(82.41Hz)

Musically speaking the first note E in the guitar is 2 octaves BELOW the second .

THIS ONLY TOUCHING THE STRINGS WITHOUT PLAYING THE LEFT HAND

[faustian bargin]

now we can talk about woodwind instruments.

a pipe with a series of holes in it. the more holes covered = the longer the effective pipe = the longer the wavelength produced = the lower the frequency.

neat huh.

next is brass. that's just messed up. i think a mechanical engineer designed the trumpet...all those valves...sheesh.