tone function

Projects General Guidance
1

I downloaded some code for music and the programmer used the tone and delay functions in a way I never saw. Example:

tone(tonePin, 523, 1499.21875);
delay(1665.79861111);
delay(0.868055555556);

I isolated each of the lines of code and each tone plays a specific note, but I don't understand the code and why they used such strange numbers. Can anyone shed some light on this?

2

Where did you find that code? Instructables? The delay() function and the tone() function take unsigned long integers. Any float passed as a parameter to either function will just be rounded down so

delay(1665.79861111);

will be 1665 and

 delay(0.868055555556);

will be 0.