Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1750/Pioneer.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4890-Pioneer.ps) >>/Users/jc/w/tmp/Tune-4890-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1750/Pioneer.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Tune-4890-Pioneer.abc 144 ABC music file with the extracted tune(s)
Tune-4890-Pioneer.ps 6 PostScript
Tune-4890-Pioneer.txt 144 Plain-text file with the extracted tune(s)
Tune-4890-get.log 4003 Log file, useful mostly for debugging
Tune-48900-get.log 1396 Log file, useful mostly for debugging
Tune-48903-get.log 4483 Log file, useful mostly for debugging
Tune-48906-get.log 4034 Log file, useful mostly for debugging
Tune-48907-get.log 4430 Log file, useful mostly for debugging
Tune-48908-get.log 1363 Log file, useful mostly for debugging
These files should be available for 24 hours.