pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9307-playf.ps) >>/Users/jc/w/tmp/Tune-9307-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/mirror/bath.ac.uk/exxhf/playf.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_9307.log 3318 Log file, useful mostly for debugging
Coll_93076.log 261969 Log file, useful mostly for debugging
Form_93073.log 832 Log file, useful mostly for debugging
Tune-9307-get.log 4228 Log file, useful mostly for debugging
Tune-9307-playf.abc 248 ABC music file with the extracted tune(s)
Tune-9307-playf.ps 34186 PostScript
Tune-9307-playf.txt 248 Plain-text file with the extracted tune(s)
Tune-93071-get.log 4047 Log file, useful mostly for debugging
Tune-93078-get.log 4006 Log file, useful mostly for debugging
These files should be available for 24 hours.