# Urgent:( pleez help?

• Nov 9th 2008, 07:13 PM
AFan
Urgent:( pleez help?
Ok here's the problem: ( thank u so much by the way)

All music is simply the counting of
sound vibrations (frequency) by the
human brain. Given that the musical
scale has twelve notes (frequencies)
per octave, frequencies can be calculated
by the formula based on the A note with
frequency 440 hertz, ¦ = 440 * 2 ^(x/12)
being in the 6th octave. Calculate the
frequency of E Flat(Eb) in the 9th octave.
• Nov 9th 2008, 07:20 PM
Prove It
Quote:

Originally Posted by AFan
Ok here's the problem: ( thank u so much by the way)

All music is simply the counting of
sound vibrations (frequency) by the
human brain. Given that the musical
scale has twelve notes (frequencies)
per octave, frequencies can be calculated
by the formula based on the A note with
frequency 440 hertz, ¦ = 440 * 2 ^(x/12)
being in the 6th octave. Calculate the
frequency of E Flat(Eb) in the 9th octave.

This is just a simple substitution.

If we say the A note in the 6th octave is the "0 note", then x = 0.

Since there are 12 notes in the octave,

A in the 7th octave gives x = 12
A in the 8th octave gives x = 24
A in the 9th octave gives x = 36.

The list of notes in each octave is...

Bb, B, C, Db, D, Eb, E, F, Gb, G, Ab, A.

So Eb is 6 higher than A.

Which means Eb in the 9th octave gives x = 42.

Thus the frequency of Eb in the 9th octave is

$\displaystyle f= 440 \times 2^{\frac{42}{12}} = 440 \times 2^{\frac{7}{2}}$.
• Nov 9th 2008, 07:38 PM
AFan
Ok Im alittle confused so I would calcualte 440*2^(44/12)=440*2^(7/2) how would i do that, i dont get it...

I'm sry I'm slow when it comes to this lol