Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Tunes/BonAccordCollection.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9160-BonAccordCollection.ps) >>/Users/jc/w/tmp/Tune-9160-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Tunes/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_91601.log 275900 Log file, useful mostly for debugging
Coll_91609.log 294165 Log file, useful mostly for debugging
Tune-9160-BonAccordCollection.abc 157 ABC music file with the extracted tune(s)
Tune-9160-BonAccordCollection.ps 6 PostScript
Tune-9160-BonAccordCollection.txt 157 Plain-text file with the extracted tune(s)
Tune-9160-get.log 4261 Log file, useful mostly for debugging
Tune-91601-get.log 5216 Log file, useful mostly for debugging
Tune-91607-get.log 4523 Log file, useful mostly for debugging
Tune-91608-CDfNH1783.abc 148 ABC music file with the extracted tune(s)
Tune-91608-CDfNH1783.pdf 2217 Portable Data Format
Tune-91608-CDfNH1783.ps 6 PostScript
Tune-91608-CDfNH1783.txt 148 Plain-text file with the extracted tune(s)
Tune-91608-get.log 6257 Log file, useful mostly for debugging
These files should be available for 24 hours.