pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-75042-abc-tutorial.ps) >>/Users/jc/w/tmp/Tune-75042-get.log 2>&1" returned status 256
http://www.mit.edu/afs/sipb/project/outland/doc/abc2ps/abc-tutorial.html

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-75042-abc-tutorial.abc 268 ABC music file with the extracted tune(s)
Tune-75042-abc-tutorial.ps 34389 PostScript
Tune-75042-abc-tutorial.txt 268 Plain-text file with the extracted tune(s)
Tune-75042-get.log 4490 Log file, useful mostly for debugging
These files should be available for 24 hours.