Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MM3/JohnFrench.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6603-JohnFrench.ps) >>/Users/jc/w/tmp/Tune-6603-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MM3/JohnFrench.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-6603-JohnFrench.abc 146 ABC music file with the extracted tune(s)
Tune-6603-JohnFrench.ps 6 PostScript
Tune-6603-JohnFrench.txt 146 Plain-text file with the extracted tune(s)
Tune-6603-get.log 4060 Log file, useful mostly for debugging
Tune-66031-WilliamWinterQuantocks.abc 159 ABC music file with the extracted tune(s)
Tune-66031-WilliamWinterQuantocks.ps 6 PostScript
Tune-66031-WilliamWinterQuantocks.txt 159 Plain-text file with the extracted tune(s)
Tune-66031-get.log 4366 Log file, useful mostly for debugging
Tune-66032-IgnatiusSancho_MCCD_v1.abc 159 ABC music file with the extracted tune(s)
Tune-66032-IgnatiusSancho_MCCD_v1.txt 159 Plain-text file with the extracted tune(s)
Tune-66032-get.log 3398 Log file, useful mostly for debugging
Tune-66037-get.log 3566 Log file, useful mostly for debugging
Tune-66038-24FavouriteDances_1784_Straight.abc 168 ABC music file with the extracted tune(s)
Tune-66038-24FavouriteDances_1784_Straight.ps 6 PostScript
Tune-66038-24FavouriteDances_1784_Straight.txt 168 Plain-text file with the extracted tune(s)
Tune-66038-get.log 4434 Log file, useful mostly for debugging
Tune-66039-get.log 1484 Log file, useful mostly for debugging
These files should be available for 24 hours.