Some empty "" chords may be causing trouble with Jenkins. Jenkins builds are stalling when generating PDFs for some morris tunes. I suspect the problem may be an empty chord "" and abc2abc's attempt to transpose it. I've been meaning to remove the chords from the horn output, because abc2abc transposes them too, which renders them not terribly useful. So get on and do it. Also remove "" from the morris tunes where it occurs.

6bcafbfac6747b619ab8b99c3bcf662171c63d2e build-default-156
c79382d6026befece54a9da29a1c64e2b2ef2443 build-default-157
6d4b2dab5fccda11d66fea2f47e153243dcc704d build-default-158
2655390868362de9ba89734351973a52cd49a69f build-default-159
7240535f9fa7f8a372961ba733958b87c11e3fa3 build-default-161
355074af991062d4649b3283f46e4f62bd07a106 build-default-162