Re: [AL] Using play_sample frequency arg to play music?

[Elias P. <el...@us...>]

On Tue, 2004-02-17 at 08:33, Captain Pork wrote:

> I'd like to write a more advanced version of this which is capable of
> playing simple melodies by setting the frequency argument of play_sample
> to values which correspond to particular notes (C, D, G# etc). 
> 
> I'm not worried about making different samples harmonise with each other,
> but just to make a series of repetitions of the same sample play a little
> tune, without having a separate wav file for each note. Does anyone have
> any idea what the frequency steps I would need to use are? Say 1000
> (unadjusted frequency) is C, does that make 2000 the next C up (IIRC from
> high school science/music, each octave doubles the freqency)? If so, how
> do I make it play the notes in between?
> 

Yes, that's correct. The formula on the link in AJ's answer also works
directly for the relative values you pass to play_sample:

frequency = base_frequency * pow (2.0, note / 12.0)

If note is 0, you get base_frequency, in this case 1000. If note is 12,
you get the double frequency, in this case 2000. From 1 to 11 you get
the values for all the notes in the octave.

-- 
Elias Pschernig <el...@us...>