Frequencies of tones

[letscode]

I am creating an application which reads letters from a file and creates sound of the corresponding to the tone associated with the letter.
Where can I find the frequencies of the tones ?
If anyone knows please post it.(e.g. Frequency of pure middle C is 265.5 Hz)

[firedraco]

Uh, Wikipedia? Why is in the Beginners forums anyway? Should probably go in lounge.

[JLBorges]

http://www.seventhstring.com/resources/notefrequencies.html (even tempered scale)

Physics links: http://www.phy.mtu.edu/~suits/notefreqs.html

[letscode]

LOL i had just visited the second link.

[Chervil]

You can work out the frequencies from scratch using three pieces of information.
1. A = 440 Hz
2. there are 12 evenly-spaced notes in an octave
3. an octave means a doubling or halving of frequency

(well, there may be other types of scale where these assumptions don't apply, but we'll ignore that).

The ratio between the frequencies of any two adjacent semitones is the 12th root of 2.

#include <iostream>
#include <iomanip>
#include <cmath>
#include <string>

    using namespace std;


int main()
{
    string notes[13] = 
    { "A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A" };

    double ratio = pow(2.0, 1.0/12.0);
    cout << fixed;
    cout << setprecision(12);
    cout << "ratio: " << ratio << endl << endl;
    
    double a = 220;
    cout << setprecision(4);
    for (int i=0; i<=12; i++)
    {
        cout << left << setw(3) << notes[i] << right << a * pow(ratio, i) << endl;
    }
    
    return 0;
}

ratio: 1.059463094359

A  220.0000
A# 233.0819
B  246.9417
C  261.6256
C# 277.1826
D  293.6648
D# 311.1270
E  329.6276
F  349.2282
F# 369.9944
G  391.9954
G# 415.3047
A  440.0000

or look here for example http://www.phy.mtu.edu/~suits/notefreqs.html