Guitar bend error

[Devon LePage]

I’m transcribing a rock guitar solo, and to engrave the many string bends I’m using Stephen MacNeil’s LilyPond code library, available here:

http://mglessons.com/lilypond/

If I use the “definitions_No-Tab.ly” file, LilyPond engraves the file with no hiccups. However, if I use the “definitions.ily” for notation and TAB, I get the following error:

Drawing systems.../Users/devon/Downloads/lilypond-archive/guitar_functions/definitions.ily:180:14: In procedure ly:event-property in _expression_ (ly:event-property (event-cause right-bound) (quote pitch)):

/Users/devon/Downloads/lilypond-archive/guitar_functions/definitions.ily:180:14: Wrong type argument in position 1 (expecting Prob): #f

Exited with return code 1.

Learning Scheme is still on my to-do list, so I don’t quite understand what’s going on here. Frustratingly, I can’t seem to localize the error - I’ve tried compiling the file with different sections commented out, but the error isn’t consistently generated. A few times it happened at bar 13, but then it happened at bar 31, and then a few more times at places in between. It reliably compiles for the first 12 bars, but that’s it.

I’ve put the LilyPond code in a Gist here:

https://gist.github.com/devonlepage/624c66513538ad6b42de0f665857ade7

This is the first third of the transcription. I’m hoping it will be enough that someone might be able to diagnose the problem. I’ve taken out all extraneous formatting code, which didn’t seem to effect the error.

I’m using Frescobaldi 2.19 with LilyPond 2.19.40. It also happens in 2.18. I would prefer to use 2.19 so that I can use an alternative music font in the final document.

I hope someone can help me figure out what’s going on.

Thanks!

-Devon LePage.