pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-95793-polka.ps) >>/Users/jc/w/tmp/Tune-95793-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/session/Intl/polka/Ševcovský-C,D-32-3.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-95793-get.log 5502 Log file, useful mostly for debugging
Tune-95793-polka.abc 1078 ABC music file with the extracted tune(s)
Tune-95793-polka.ps 38903 PostScript
Tune-95793-polka.txt 1078 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.