Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1791/Nelson.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2545-Nelson.ps) >>/Users/jc/w/tmp/Tune-2545-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1791/Nelson.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-2545-Nelson.abc 143 ABC music file with the extracted tune(s)
Tune-2545-Nelson.ps 6 PostScript
Tune-2545-Nelson.txt 143 Plain-text file with the extracted tune(s)
Tune-2545-get.log 3982 Log file, useful mostly for debugging
Tune-25451-get.log 4074 Log file, useful mostly for debugging
Tune-25454-Kohlers1.abc 145 ABC music file with the extracted tune(s)
Tune-25454-Kohlers1.pdf 2217 Portable Data Format
Tune-25454-Kohlers1.ps 6 PostScript
Tune-25454-Kohlers1.txt 145 Plain-text file with the extracted tune(s)
Tune-25454-get.log 4824 Log file, useful mostly for debugging
Tune-25455-KittyBridges_1745_VO.abc 156 ABC music file with the extracted tune(s)
Tune-25455-KittyBridges_1745_VO.ps 6 PostScript
Tune-25455-KittyBridges_1745_VO.txt 156 Plain-text file with the extracted tune(s)
Tune-25455-get.log 4283 Log file, useful mostly for debugging
Tune-25456-WilliamWinterQuantocks.abc 158 ABC music file with the extracted tune(s)
Tune-25456-WilliamWinterQuantocks.pdf 2217 Portable Data Format
Tune-25456-WilliamWinterQuantocks.ps 6 PostScript
Tune-25456-WilliamWinterQuantocks.txt 158 Plain-text file with the extracted tune(s)
Tune-25456-get.log 5085 Log file, useful mostly for debugging
Tune-25457-get.log 4205 Log file, useful mostly for debugging
These files should be available for 24 hours.