pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-20132-042_Retreat.ps) >>/Users/jc/w/tmp/Tune-20132-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Urbani_Liston/1800/042_Retreat.abc

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Tune-20132-042_Retreat.abc 567 ABC music file with the extracted tune(s)
Tune-20132-042_Retreat.ps 35104 PostScript
Tune-20132-042_Retreat.txt 567 Plain-text file with the extracted tune(s)
Tune-20132-get.log 13368 Log file, useful mostly for debugging
These files should be available for 24 hours.