pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1142-Chestnut.ps) >>/Users/jc/w/tmp/Tune-1142-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/mirror/colinhume.com/Chestnut.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
Coll_11424.log 263379 Log file, useful mostly for debugging
Form_11429.log 825 Log file, useful mostly for debugging
Tune-1142-Chestnut.abc 382 ABC music file with the extracted tune(s)
Tune-1142-Chestnut.ps 33835 PostScript
Tune-1142-Chestnut.txt 382 Plain-text file with the extracted tune(s)
Tune-1142-get.log 4230 Log file, useful mostly for debugging
Tune-11423-get.log 2156 Log file, useful mostly for debugging
These files should be available for 24 hours.