pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-24381-petron.ps) >>/Users/jc/w/tmp/Tune-24381-get.log 2>&1" returned status 256
http://www.nigelgatherer.com/tunes/abc/abc1/petron.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-24381-get.log 4204 Log file, useful mostly for debugging
Tune-24381-petron.abc 291 ABC music file with the extracted tune(s)
Tune-24381-petron.ps 35429 PostScript
Tune-24381-petron.txt 291 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.