Generating Audio In C programming

This is a question regarding C Programming: i am looking to generate audio using C Code. for this i am looking to generate a square wave function (does not have to be a square wave can be any wave form really) which plays musical notes which last for about 30 seconds. After looking on the internet and message boards i have come across the sound(), nosound() and delay() codes for C, but i can only generate a single tone which lasts for one second. below is the code which i attempted to put together, this code below did not produce anything just errors when i was trying to compile the code.

#include <stdio.h>
#include <dos.h>

void my_sounds(void);

int music(int pitch, int time)
{
sound(pitch);
delay(time);
nosound();
return(0);
}


void       my_sounds(void)
 {
      sound(130);            /* make a sound at 500 Hz.*/
      delay(2000);            /* pause for 2000 milliseconds = 2 seconds  */
      nosound();
      return(0);

      sound(137);
      delay(2000);
      nosound();
      return(0);

      sound(145);
      delay(2000);
      nosound();
      return(0);

      sound(155);
      delay(2000);
      nosound();
      return(0);

      sound(166);
      delay(2000);
      nosound();
      return(0);

      sound(176);
      delay(2000);
      nosound();
      return(0);

      sound(185);
      delay(2000);
      nosound();
      return(0);

      sound(195);
      delay(2000);
      nosound();
      return(0);

      sound(207);
      delay(2000);
      nosound();
      return(0);

      sound(220);
      delay(2000);
      nosound();
      return(0);

      sound(235);
      delay(2000);
      nosound();
      return(0);

      sound(260);
      delay(2000);
      nosound();
      return(0);

      sound(275);
      delay(2000);
      nosound();
      return(0);

      sound(290);
      delay(2000);
      nosound();
      return(0);

      sound(311);
      delay(2000);
      nosound();
      return(0);

      sound(333);
      delay(2000);
      nosound();
      return(0);

      sound(350);
      delay(2000);
      nosound();
      return(0);

      sound(370);
      delay(2000);
      nosound();
      return(0);

      sound(390);
      delay(2000);
      nosound();
      return(0);

      sound(415);
      delay(2000);
      nosound();
      return(0);

      sound(440);
      delay(2000);
      nosound();
      return(0);

      sound(470);
      delay(2000);
      nosound();
      return(0);

      sound(490);
      delay(2000);
      nosound();
      return(0);

      sound(520);
      delay(2000);      
      nosound();            /* turn off sound      */
      return(0);
 }

Does anyone know how i would go about generating some type of wave function which can play musical notes in C programming.

Many Thanks,

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