# Thread: Logarithms, octaves and semitones

1. ## Logarithms, octaves and semitones

An orchestra tunes to a frequency of 440, which sounds the A above middle C. Each octave higher doubles the frequency, and each of the 12 semitones in the octave increases the frequency in the same ratio.

a)What is the ratio? 880= 440 x b^12, b= 1.059

b)Find the frequency of middle C. I can't work this out. The answer is supposedly 262 but I can't get this.

c) Where on the scale is a note with a frequency of 600?

I cant get the answer to this either which the book says is "between D and D#".

2. Originally Posted by woollybull
An orchestra tunes to a frequency of 440, which sounds the A above middle C. Each octave higher doubles the frequency, and each of the 12 semitones in the octave increases the frequency in the same ratio.

a)What is the ratio? 880= 440 x b^12, b= 1.059

b)Find the frequency of middle C. I can't work this out. The answer is supposedly 262 but I can't get this.

c) Where on the scale is a note with a frequency of 600?

I cant get the answer to this either which the book says is "between D and D#".
See if this helps: Frequency of Middle C

Be sure to read the editor's supplement in regards to the error presented by someone else and the correction of that error.

3. ## Further assistance required

Thanks for trying to help but I still can't work out what the middle A above middle C means.
This is the only text question on the topic of logarithms that has me stumped.
Thanks.