Exactly that /|.
OpenGL has nothing to do with sounds…
OpenAL is an audio library that have a similar syntax, but still it doenst have any real connection with Opengl.
basically you generate sounds by generating a soundwave into a buffer, and send that buffer to the soundcard with an dexcription on how fast it should read the values from that buffer and change the DAC to the speakers to the buffers value.
If u are talking about creating sounds that u can use in your applications, then this might help you.
If you play any instrument and its electronic, it will most probably have a MIDI output port that you can connect to your PC. Pianos can create a whole host of sounds and you can use software (some might be available on the net) to record those sounds by using the MIDI port of the instrument and your PC.
If you are not a musician, then you can use software which allow you to create sounds by varying the frequency, chords and other parameters. They allow you to compose the music entirely on the PC but again, you need to have atleast some knowledge of Music.
Or you can use readymade sounds from the net.
After the music is ready, as already pointed out, you use OpenAL to include it in your applications.
Hope this helps.
Abhijeet.(www.emadness.tk)
or simply use one those API by a google search :
- Bass
- Fmod
they provide sync, fft datas etc 
Stv / Razor1911 demodivision.
As far as i can tell FMOD is the best sound API, because it is very easy and can load a lot of sound formats (OpenGL can only read wav files, at least when i tried it out).
Jan.