Well if it can be sped up or down, that's not an issue.  I don't care about the speed since most notes will repeat (in order to be held out) anyways.  After all, on computer midi, if you start with a single recorded note (like a piano note), the sound will run faster and faster the higher up you go.

This also looks like an interesting topic.  I'm curious as well.  Thanks for asking a great question Hot Dog.

Well, I'm tossing around the idea with having about 16 "midi" instruments and making music for S.A.D. for 15 Mhz calculators.  If I can't get enough channels and can't change single notes, however, it ain't going to happen

Your routine is built to play how many bits per sample, and at what sample rate?

Well, it's not actually my routine.  But it is 11 Khz, 8-bit mono

So are you wanting some sort of WAV playback, or do you want beeps?

WAV.  What I'm looking at is a recorded note (such as .1 seconds of violin, like they do with midi), and since the code above can play waves, I'm wondering if that note can be adjusted for length and pitch, and played in two or 4 channels.

Also I sometimes notice references to your tutorials on other forums or IRC when someone asks what's a good ASM tutorial, plus your tutorials are downloaded quite often, so it tells you did an amazing job on them so far.

Dude, thanks for telling me that!  It was definitely my goal to make ASM easy to understand.

Unfortunately, though, the pdf for lesson 4 might not be up for some time.  It's low on my list of priorities

Lesson 15 is now up.  You won't learn to input names yet, because I realized that the lesson was starting to get too long.

Now I'll be doing lesson 17, which teaches you how to draw sprites!  For all you eager beavers, that might come as soon as next week.

For those of you who think you will laugh and point at me for asking a reasonable question, please leave immediately.

So, this is part of the code for PlayWav:

di           
 ld   a, 0FDh
 out  (01h), a 

main:
 ld   a, (hl)
 and  0Fh
 ld   c, a   
 call Label15
 ld   a, (hl)
 srl  a       
 srl  a       
 srl  a       
 srl  a       
 and  0Fh
 ld   c, a
 push iy
 pop  iy ;slow this down a little
 call Label15
 inc  hl     
 dec  de     
 ld   a, d   
 push iy ;slow this down a little
 pop  iy
 or   e       
 jr   nz,main
 ei         
 ret
         
quit:
 pop af
 pop af ;fix the stack
 pop af
 ret

Label15:
 ld   b, c   
 inc  b       
 ld   a, 0D3h

Label18:
 out  (00h), a 
 djnz Label18
 ld   a, 10h
 sub  c       
 ld   b, a   
 ld   a, 0D0h

Label19:
 out  (00h), a 
 djnz Label19
 ret

1. If I were to use a custom sound, one single recorded note, would it be possible to adjust the frequency and duration of that sound to allow more notes?
2. Would it be possible to have 2--or even 4--channels of said single recorded notes at said frequencies and durations?

I'm not asking for code (cause I have an idea of what I want to do), I'm just asking if it's reasonably possible.

Sounds great, Iambian!  Keep up the good work!