You will need to post some code to be able to get the correct help.

[edited]

 SAMPLE *music=load_wav("edit.wav");

this code doesn't include checking the pointers to see if they're null--which is returned when the file cannot be loaded or cannot be found.

if(music == NULL)printf("AHH!\n");

Example code in the docs shows this:

  SAMPLE *sample = load_wav("scream.wav");
      if (!sample)
   abort_on_error("Couldn't scare user!"); // you don't have to use abort_on_error

Also, there's allegro_error which gets populated on errors with a message describing the error:

https://www.allegro.cc/manual/4/api/using-allegro/allegro_error

It's a good idea to check that if things are breaking somewhere.

The latest version that works with djgpp is 4.2.3 with the corresponding makefile.

The most modern version of Allegro doesn't work with DJGPP or DOS, and is hardware accelerated unlike Allegro 4. Try Allegro 5 today.

I don't have the docs for Allegro 3 (which dates from last century) but A4 is pretty much the same (and I recommend you get Allegro 4 even if you don't want to go to 5)

The description of play_sample is (https://liballeg.org/stabledocs/en/alleg026.html#play_sample)

int play_sample(const SAMPLE *spl, int vol, int pan, int freq, int loop);

Triggers a sample at the specified volume, pan position, and frequency. 
The parameters `vol' and `pan' range from 0 (min/left) to 255 (max/right). 
Frequency is relative rather than absolute: 1000 represents the frequency 
that the sample was recorded at, 2000 is twice this, etc. If `loop' is 
not zero, the sample will repeat until you call stop_sample(), and can be 
manipulated while it is playing by calling adjust_sample().

So your play_sample(music,255,90,22050,0) is not correct, try play_sample(music,255,128,1000,0)

Can you get any sound out of Allegro (e.g. using the demo game or example programs)? If not you may have to edit your allegro.cfg to pick a usable sound card.

[edit] - is your problem that it doesn't load (stated in your first post) or it crashes (second post)?

If the wav file is null after you load it, then you probably aren’t loading it. You need to make sure the wav file is in the same folder where your executable runs from; if you’re using Codeblocks, for example, the program will run from the main project folder, not from /bin/debug. Try to load the file with the full path, for example c:\myproject\music.wav (or wherever it actually is). That way you can confirm that if the wav isn’t null, the audio works properly.

It may also be an unsupported wav file.

Allegro 3.0 is REALLY old. You should at least update to 4.2.3. It has the same API but there are years and years of bug fixes. That alone may solve your .wav issue.

freq in the parameter list is the frequency you want to play the sample at. This should almost always be 1000 for normal speed.