pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-5303-NellyBly1_C24.ps) >>/Users/jc/w/tmp/Tune-5303-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/Square/NellyBly1_C24.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-5303-NellyBly1_C24.abc 423 ABC music file with the extracted tune(s)
Tune-5303-NellyBly1_C24.ps 32675 PostScript
Tune-5303-NellyBly1_C24.txt 423 Plain-text file with the extracted tune(s)
Tune-5303-get.log 4455 Log file, useful mostly for debugging
Tune-53033-get.log 5555 Log file, useful mostly for debugging
These files should be available for 24 hours.