translation functions

[Ken]

Hi

I'm not a lilypond expert, but something has changed in the last version or so. 
 
I have many banjo tablatures that I've worked out in lilypond that compiled 
nicely and produced midi etc.  Now, when I try to edit and recompile, I get 

Parsing...
Interpreting music... /usr/share/lilypond/2.15.39/scm/translation-
functions.scm:289:37: In procedure ly:pitch-semitones in expression (ly:pitch-
semitones (list-ref tuning #)):
/usr/share/lilypond/2.15.39/scm/translation-functions.scm:289:37: Wrong type 
argument in position 1 (expecting Pitch): -10
Exited with return code 1.

This seems to be happening with all of them.  Has there been a change in the 
way 
string tunings are coded?