Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MM2/MMM2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8277-MMM2.ps) >>/Users/jc/w/tmp/Tune-8277-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MM2/MMM2.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_8277.log 289011 Log file, useful mostly for debugging
Tune-8277-MMM2.abc 140 ABC music file with the extracted tune(s)
Tune-8277-MMM2.ps 6 PostScript
Tune-8277-MMM2.txt 140 Plain-text file with the extracted tune(s)
Tune-8277-get.log 3928 Log file, useful mostly for debugging
Tune-82770-get.log 3353 Log file, useful mostly for debugging
Tune-82773-24CountryDances_1771_Thompson.abc 172 ABC music file with the extracted tune(s)
Tune-82773-24CountryDances_1771_Thompson.txt 172 Plain-text file with the extracted tune(s)
Tune-82773-get.log 3566 Log file, useful mostly for debugging
Tune-82777-get.log 4136 Log file, useful mostly for debugging
These files should be available for 24 hours.