To port from Addmusic 4 to AddmusicM is even simpler, in my opinion.
1. Getting the samples.
Get Split700 and create a .bat file with this content:
split700 -M --force *.spc
You can leave out --force, if you don't want the program to rip all samples, even invalid ones. I honestly recommend not to do that though, since it oftenly doesn't rip valid samples, so yeah...just leave it that way, I guess.
Now get the SPC you want the samples from, the sample SPC from Addmusic4 songs works fine, too, if you know the sample's slot, otherwise use SPC700 player and play the song as usual, it will display the sample.
Once done and all samples ready, you'd want to open blist.txt and insert your samples there. Leave the originaly in there and below add this:
Just reanme sample1/sample2 to your .brr files in the brr folder.
2. Setting the samples in the actual song.
AddmusicM uses the $f3 command to load samples and unlike the $e5 command, there's no need to do sample+$80 or anything, instead you create a header for your song, which will set the samples to be used, e.g.
XX being a number from 05-FF (the PCM set)
_20_21_FF <- This one loads sample 20 and 21 (sample1 and sample2 in this case). FF tells AddmusicM to stop loading any samples in that song (it's neccessary!).
After you've written the header it should now look like this:
s10 <- PCM set 10
_20_21_FF <- samples 20,21
Replacing the samples, how?
In Addmusic4 you'll find the $e5 command, e.g.
$e5 $90 $04 <- This one would load sample 10 from a .bnk file.
But in AddmusicM you will need this:
$f3 $20 $04 <- This one will load sample 20 (sample1.brr) from the header.
The pitch is the same from my experience.
NOTE: Make sure that the samples in blist.txt are the same written in your song's header!
Hope that helps. Otherwise feel free to ask me.