Though This is an extremely dumb question to be asking on a forum with expert guitar players.... i have only been playing for 2 and a half years. I am studying theory because i do not know it.... could some one please explain the purpose of octaves and what they do in the general sense.... thx

Basicly all aural frequencies are divided in notes, ie:

A Bb B C C# D Eb E F F# G G#

A full spectrum of these notes is called an octave. All octaves have the same notes, but their higher or lower.
The A note on an high octave is higher than the A note on a lower octave, but their both A notes.

Just think of this, the open E on the 6th string on your guitar is the same note as on the 12th fret of the 6th string, but its higher.

I don't realy know what purpose octaves have, except that they divided the whole hear-able aural spectrum while still maintaining 12 universal notes.

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Play the open 6th string. Then play the 12th fret on that same strings. Thats an octave.
Its just the same note but an octave higher.

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You ever seen a piano? You notice it seems to be divided into sections by 7 white keys and 5 black keys? An octave is one of those section, basically one section contains all possible notes, but only at one range. Another way of explaining an octave is the exact same note, but at a higher pitch.

And as CC was explaining, these piano "sections" I was talking about are the exact same thing as the open string to the 12th fret on a guitar. There are more ways than one to play octaves on a guitar though. One popular way artists play octaves is by making a power chord formation (placing one finger on a string, and then playing 2 frets higher and one string higher) and then moving the finger on the 5th(which is the note being played 2 frets higher and one fret higher) to the next highest string, and muting the one in between, looking like this:

l---5----l
l--------l
l---3----l

K thx....

you can amke up cool ass shit with two guitars playing higher or lower octaves too.

your not suppose to mix sharps and flats...

basically theres the musical alphabet like above
A B C D E F G (with accidentals in between i.e. A# C# ect)

an actave is when you go through the musical alphabet and come back to the same note so one octave would be
..................A B C D E F G A B C D E F G A
starting note^...one octave^..two octaves^

on sheet music it would look like such

---------------
----@---------- (1st D octave)
---------------
---------------
---------------
@ (D note)

on guitar think of it this way every 12 half steps (or frets) is an octave so from open E to 12 fret on E is one octave then from 12 fret E to 24 fret E is another octave

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Me and my friend octave when we solo. It sounds pretty cool. Especially when you're playing scales

Sure. Traditionaly, you either had sharps or flats. But modern musicians (guitarists!) tend to use the simplified mixed one. Right now, thats what people use.

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really? i have never seen that "mixed" one before

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You use the traditional way in theory, because Cbbbbb or A### is also possible. But in normal 'speaking language', musicians stick to the mixed one.

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Psh, what the hell There is absolutly no such thing as "Cbbbbb."
Sharps and flats are used according to the SCALE that's being played. Saying a G# in the key of C major is not right. It's an Ab. The ONLY way you can get away with writing a G# is if you modulated to another key. Incidently, obviously, you're in a new key and the way to get there would be to use a secondary dominant.

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maybe not a Cbbbb but there are such things as a A## it just hads a whole note to the originial note so its basically a B

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It was always easier for me to think about it like this, Its half of your string. Thats why when you dont press on 12 but hold your fringer on the string it makes a harmonic. But I think of guitar as a big math problem when I play, like relating notes like ok if i hit my 12 on my bottom E then thats going to be minus 5 (5 because when you tune you hold the string down on the 5th fret except on G) on my A so that would be the 7th fret ok so I cant play my 7th on A after I hit my 12 on E. But it gets easier once you start playing long enough to know which place on which string should sound like and will sound like relating to the note you just played. You'll get it after a while

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octaves would be a good thing to learn.. many kick ass bands use them to get extra kick into the song. and in some ways it will also help u develop guitar solos if thats ur thing, but still learn scales and shit.

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Umm buddy, thats not a bodom quote. It may be the intro to Follow the Reaper, but give credit where credit is due, John Donne.

ok ill change that later than, if i remember, cuz i have to go somewhere.

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If we are going to speak about A# and Bb. I must say that teorically aren´t the same note. And music players (like violin players, for example) do this diferenciation.

I know that basically it sound the same, because (in our guitars) we only have one position to A# or Bb.(the same position). But fretless instruments had one position for A# and a litlle diferent for Bb.

See ya

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they are the same note, a# is the enharmonic value of Bb
every instrument that i can think of has only one spot to play the note. its just sometimes you have to use one name over the other mainly for scales and what not

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That all depends on what scale you're playing. In the scale of F# major, the major 7th or E# should be played a little bit higher than say an F (natural) in the key of Gb major. That way we have a little more of that dominant sound-the hair raising note before you resolve on the tonic. It may be out of tune, but if you're musical and romantic enough, you can really sell it.
Behemoth, you're only a little right when you say they're not the same note. An example of what you said would be (No offense, but I doubt you "really" knew this), is that an A 440 is not the same note as an A 880-in other words, the octave above that A 440. They ARE a different pitch. The 880 pitch is a little flatter. The higher you go the flatter you get. 100 years or so ago, orchestras tuned to the tonic to every song. Since that takes ages, nowadays, we tune according to one A, and all songs are played with the same notes. It makes it easier. The only drawback of this is that the fact that when people who have perfect pitch say "the curse of perfect pitch," they really mean that.

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first off in no way is anything powersofterror said wrong, but i have heard from a few music proffesors that certian string players can hear a slight diffrence between enharmonic pitches such as A#, Bb.

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Ok, here's the deal guys. In natural occurring pure intervallic evolutions, a B# in not equivalent to a C. Likewise, a Dbb is not equivalent to a C. Both B# and Dbb are audibly different from C. However, it was discovered in early classical times (European) that if you take an almost imperceptible amount (2 cents) away from each 5th, you can get a Cycle of 5ths. Suddenly we have a system which is much more usefull, the snake eats it's tail in the circle of fifths, whereas if we didn't use this system the snake would almost eat it's tail forever. Both systems have their advantages, but the current system is extremely usefull, which is why we use it. Bach was one of the first people to demonstrate this and his music was very successful in promoting this system.

The difference between octaves is frequency. The next higher octave is vibrating exactly twice as fast as it's lower counterpart, 2 octaves higher is vibrating 4 times faster than the original note and so on and so fourth.

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funny.....the last 2 posts just repeated basically what I was getting at.... You stupid people, we are arguing against each other in agreement.

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Well not really, since the system we use, a B# is the exact same note as a C. There is no difference.

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I was never arguing according to systems, but instead simpily supporting behemoths claim that because of the nature of the technique string players use (absense of frets) a few develope hearing more percise than a half step.

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In that regard you are exactly correct.

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Ok, you can argue enharmonics all day, but getting back to definitions, an octave is a fancy name for all frequencies (and therefore pitches or even subpitches) between two boundary frequencies where the upper boundary is exactly twice the frequency of the lower.

The special property of two frequencies an octave apart deals with their beat frequencies. The beat frequency is the the difference between the two frequencies. Like when you're tuning, and two notes are 1Hz apart, you get a warble at 1Hz. We tune by listening to the warble and trying to eliminate it.

For frequencies an octave apart, the warble (beat frequency) is of the same frequency as the lower boundary. Because 880Hz - 440Hz = 440Hz, the warble (beat frequency) that we generate is in tune with the other two note. This is where resonance comes from.

You're smart

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its also vibrating twice as fast,
say you hum a C then you hum a C an octave higher your vocal chords will be vibrating twice as fast

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