Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1758/OriginallyMine.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9423-OriginallyMine.ps) >>/Users/jc/w/tmp/Tune-9423-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1758/OriginallyMine.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_94238.log 283412 Log file, useful mostly for debugging
Tune-9423-OriginallyMine.abc 151 ABC music file with the extracted tune(s)
Tune-9423-OriginallyMine.ps 6 PostScript
Tune-9423-OriginallyMine.txt 151 Plain-text file with the extracted tune(s)
Tune-9423-get.log 4146 Log file, useful mostly for debugging
Tune-94230-JamesJohnson_ScotsMusicalMuseumV4-V2.abc 175 ABC music file with the extracted tune(s)
Tune-94230-JamesJohnson_ScotsMusicalMuseumV4-V2.txt 175 Plain-text file with the extracted tune(s)
Tune-94230-get.log 6872 Log file, useful mostly for debugging
Tune-94232-get.log 4540 Log file, useful mostly for debugging
Tune-94234-get.log 17950 Log file, useful mostly for debugging
Tune-94235-get.log 4292 Log file, useful mostly for debugging
Tune-94237-get.log 5457 Log file, useful mostly for debugging
Tune-94238-get.log 5650 Log file, useful mostly for debugging
These files should be available for 24 hours.