Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1781/Kohlers1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1967-Kohlers1.ps) >>/Users/jc/w/tmp/Tune-1967-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1781/Kohlers1.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-1967-Kohlers1.abc 145 ABC music file with the extracted tune(s)
Tune-1967-Kohlers1.ps 6 PostScript
Tune-1967-Kohlers1.txt 145 Plain-text file with the extracted tune(s)
Tune-1967-get.log 4022 Log file, useful mostly for debugging
Tune-19673-get.log 3576 Log file, useful mostly for debugging
Tune-19674-get.log 5587 Log file, useful mostly for debugging
Tune-19676-all.abc 171 ABC music file with the extracted tune(s)
Tune-19676-all.txt 171 Plain-text file with the extracted tune(s)
Tune-19676-get.log 3206 Log file, useful mostly for debugging
Tune-19678-203_MissBrandlingOfGosforthsReel.abc 978 ABC music file with the extracted tune(s)
Tune-19678-203_MissBrandlingOfGosforthsReel.gif 0 Graphics Interchange Format, the proprietary scan-line picture format
Tune-19678-203_MissBrandlingOfGosforthsReel.ps 38585 PostScript
Tune-19678-203_MissBrandlingOfGosforthsReel.txt 978 Plain-text file with the extracted tune(s)
Tune-19678-get.log 5894 Log file, useful mostly for debugging
These files should be available for 24 hours.