pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9668-Kerr_MM3-V2.ps) >>/Users/jc/w/tmp/Tune-9668-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Kerr/MM3/Kerr_MM3-V2.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_96689.log 259149 Log file, useful mostly for debugging
Tune-9668-Kerr_MM3-V2.abc 266 ABC music file with the extracted tune(s)
Tune-9668-Kerr_MM3-V2.ps 32776 PostScript
Tune-9668-Kerr_MM3-V2.txt 266 Plain-text file with the extracted tune(s)
Tune-9668-get.log 4462 Log file, useful mostly for debugging
Tune-96681-get.log 0 Log file, useful mostly for debugging
These files should be available for 24 hours.