pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-40784-ConstantBilly2.ps) >>/Users/jc/w/tmp/Tune-40784-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/500/ConstantBilly2.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-40784-ConstantBilly2.abc 626 ABC music file with the extracted tune(s)
Tune-40784-ConstantBilly2.ps 34465 PostScript
Tune-40784-ConstantBilly2.txt 626 Plain-text file with the extracted tune(s)
Tune-40784-get.log 4980 Log file, useful mostly for debugging
These files should be available for 24 hours.