Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1780/Gow-CSR-abc2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6668-Gow-CSR-abc2.ps) >>/Users/jc/w/tmp/Tune-6668-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1780/Gow-CSR-abc2.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-6668-Gow-CSR-abc2.abc 149 ABC music file with the extracted tune(s)
Tune-6668-Gow-CSR-abc2.ps 6 PostScript
Tune-6668-Gow-CSR-abc2.txt 149 Plain-text file with the extracted tune(s)
Tune-6668-get.log 4108 Log file, useful mostly for debugging
Tune-66680-get.log 4006 Log file, useful mostly for debugging
Tune-66686-KittyBridges_1745_VO.abc 157 ABC music file with the extracted tune(s)
Tune-66686-KittyBridges_1745_VO.ps 6 PostScript
Tune-66686-KittyBridges_1745_VO.txt 157 Plain-text file with the extracted tune(s)
Tune-66686-get.log 4203 Log file, useful mostly for debugging
Tune-66689-Garryowen_with_variations_.abc 163 ABC music file with the extracted tune(s)
Tune-66689-Garryowen_with_variations_.ps 6 PostScript
Tune-66689-Garryowen_with_variations_.txt 163 Plain-text file with the extracted tune(s)
Tune-66689-get.log 7670 Log file, useful mostly for debugging
These files should be available for 24 hours.