Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Book23/GentlemansMagazine.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7393-GentlemansMagazine.ps) >>/Users/jc/w/tmp/Tune-7393-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Book23/GentlemansMagazine.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_73931.log 287140 Log file, useful mostly for debugging
Coll_73936.log 291356 Log file, useful mostly for debugging
Coll_73938.log 289950 Log file, useful mostly for debugging
Tune-7393-GentlemansMagazine.abc 157 ABC music file with the extracted tune(s)
Tune-7393-GentlemansMagazine.ps 6 PostScript
Tune-7393-GentlemansMagazine.txt 157 Plain-text file with the extracted tune(s)
Tune-7393-get.log 10303 Log file, useful mostly for debugging
Tune-73930-Remick.abc 148 ABC music file with the extracted tune(s)
Tune-73930-Remick.txt 148 Plain-text file with the extracted tune(s)
Tune-73930-get.log 3144 Log file, useful mostly for debugging
Tune-73936-get.log 1389 Log file, useful mostly for debugging
Tune-73937-Gow-CSR-abc1.abc 151 ABC music file with the extracted tune(s)
Tune-73937-Gow-CSR-abc1.pdf 2217 Portable Data Format
Tune-73937-Gow-CSR-abc1.ps 6 PostScript
Tune-73937-Gow-CSR-abc1.txt 151 Plain-text file with the extracted tune(s)
Tune-73937-get.log 4954 Log file, useful mostly for debugging
Tune-73938-get.log 6938 Log file, useful mostly for debugging
These files should be available for 24 hours.