The parts to look at are

lines 41, 45 & 48 These require changing to your prefences

41 is the wanted listening playlist size. For me set to 25 it give a final playlist of
 
30ish tracks as the sums (see below) are made to round up each result so it will never be below 25

45 Is your required playlist title. This can be anything of 4 characters or more.

I set mine to "Ymir" and it calls the listening playlists "Ymir Playlist No.1" etc...
Also tried "The strange case of Walter Mitty" and got "The strange case of Walter Mitty Playlist No.1"

48 is the last character of your decades playlist name.

Both of ours are 9 so that doesn't need changing. Might be useful in futuire adventures though.

ALSO

The sums bit at lines 207 - 224

There must be a way of doing this simpler! But everything I try goes tits up!!

FINALLY

Lines 273 - 275 are where the databse is reset if all (more than 99%) have been allocated.
It will do this automatically when this happens. BUT, If you require to do one early
change the ">" to a "<" and run the app again and it will zero every track.
DON'T FORGET TO CHANGE IT BACK THOUGH :-)

End of file. Let me know if there is anything else you need to know.