pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-42421-NowIsTheMonthOfMaying.ps) >>/Users/jc/w/tmp/Tune-42421-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/src/jcabc2ps/abc/NowIsTheMonthOfMaying.abc

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Tune-42421-NowIsTheMonthOfMaying.abc 1156 ABC music file with the extracted tune(s)
Tune-42421-NowIsTheMonthOfMaying.ps 43356 PostScript
Tune-42421-NowIsTheMonthOfMaying.txt 1156 Plain-text file with the extracted tune(s)
Tune-42421-get.log 4634 Log file, useful mostly for debugging
These files should be available for 24 hours.