pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4793-30663_Mississippi_Hornpipe.ps) >>/Users/jc/w/tmp/Tune-4793-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/EliasHowe/MusiciansCompanionP3/30663_Mississippi_Hornpipe.abc

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_4793.log 771220 Log file, useful mostly for debugging
Coll_47937.log 452811 Log file, useful mostly for debugging
Coll_47939.log 1365432 Log file, useful mostly for debugging
Form_47930.log 988 Log file, useful mostly for debugging
Tune-4793-30663_Mississippi_Hornpipe.abc 823 ABC music file with the extracted tune(s)
Tune-4793-30663_Mississippi_Hornpipe.ps 36123 PostScript
Tune-4793-30663_Mississippi_Hornpipe.txt 823 Plain-text file with the extracted tune(s)
Tune-4793-get.log 4978 Log file, useful mostly for debugging
These files should be available for 24 hours.