Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/1784/Playford_AB.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7930-Playford_AB.ps) >>/Users/jc/w/tmp/Tune-7930-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/1784/Playford_AB.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-7930-Playford_AB.abc 148 ABC music file with the extracted tune(s)
Tune-7930-Playford_AB.ps 6 PostScript
Tune-7930-Playford_AB.txt 148 Plain-text file with the extracted tune(s)
Tune-7930-get.log 10405 Log file, useful mostly for debugging
Tune-79300-get.log 16554 Log file, useful mostly for debugging
Tune-79301-24FavouriteDances_1783_Straight.abc 168 ABC music file with the extracted tune(s)
Tune-79301-24FavouriteDances_1783_Straight.ps 6 PostScript
Tune-79301-24FavouriteDances_1783_Straight.txt 168 Plain-text file with the extracted tune(s)
Tune-79301-get.log 4434 Log file, useful mostly for debugging
These files should be available for 24 hours.