Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/reel/CDfNH1783.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2438-CDfNH1783.ps) >>/Users/jc/w/tmp/Tune-2438-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/reel/CDfNH1783.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-2438-CDfNH1783.abc 146 ABC music file with the extracted tune(s)
Tune-2438-CDfNH1783.ps 6 PostScript
Tune-2438-CDfNH1783.txt 146 Plain-text file with the extracted tune(s)
Tune-2438-get.log 4043 Log file, useful mostly for debugging
Tune-24382-AbrahamMackintosh.abc 154 ABC music file with the extracted tune(s)
Tune-24382-AbrahamMackintosh.txt 154 Plain-text file with the extracted tune(s)
Tune-24382-get.log 3308 Log file, useful mostly for debugging
Tune-24383-get.log 5265 Log file, useful mostly for debugging
Tune-24387-24CountryDances_1771_Randall.abc 165 ABC music file with the extracted tune(s)
Tune-24387-24CountryDances_1771_Randall.ps 6 PostScript
Tune-24387-24CountryDances_1771_Randall.txt 165 Plain-text file with the extracted tune(s)
Tune-24387-get.log 4488 Log file, useful mostly for debugging
These files should be available for 24 hours.