Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1758/endo.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6880-endo.ps) >>/Users/jc/w/tmp/Tune-6880-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1758/endo.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-6880-endo.abc 141 ABC music file with the extracted tune(s)
Tune-6880-endo.ps 6 PostScript
Tune-6880-endo.txt 141 Plain-text file with the extracted tune(s)
Tune-6880-get.log 3940 Log file, useful mostly for debugging
Tune-68800-get.log 4678 Log file, useful mostly for debugging
Tune-68801-get.log 5030 Log file, useful mostly for debugging
Tune-68802-get.log 17251 Log file, useful mostly for debugging
Tune-68808-endo.abc 141 ABC music file with the extracted tune(s)
Tune-68808-endo.pdf 2217 Portable Data Format
Tune-68808-endo.ps 6 PostScript
Tune-68808-endo.txt 141 Plain-text file with the extracted tune(s)
Tune-68808-get.log 10055 Log file, useful mostly for debugging
These files should be available for 24 hours.