Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1776/BonAccordCollection.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9827-BonAccordCollection.ps) >>/Users/jc/w/tmp/Tune-9827-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1776/BonAccordCollection.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_98271.log 290412 Log file, useful mostly for debugging
Tune-9827-BonAccordCollection.abc 156 ABC music file with the extracted tune(s)
Tune-9827-BonAccordCollection.ps 6 PostScript
Tune-9827-BonAccordCollection.txt 156 Plain-text file with the extracted tune(s)
Tune-9827-get.log 4257 Log file, useful mostly for debugging
Tune-98271-Jean_Henry_dAnglebert_PdC1.abc 169 ABC music file with the extracted tune(s)
Tune-98271-Jean_Henry_dAnglebert_PdC1.pdf 2217 Portable Data Format
Tune-98271-Jean_Henry_dAnglebert_PdC1.ps 6 PostScript
Tune-98271-Jean_Henry_dAnglebert_PdC1.txt 169 Plain-text file with the extracted tune(s)
Tune-98271-get.log 5386 Log file, useful mostly for debugging
Tune-98275-_.abc 138 ABC music file with the extracted tune(s)
Tune-98275-_.ps 6 PostScript
Tune-98275-_.txt 138 Plain-text file with the extracted tune(s)
Tune-98275-get.log 3802 Log file, useful mostly for debugging
These files should be available for 24 hours.