Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/abc/session/RoM/Golden_Slippers-G-32-4.abc/polka"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4088-polka.ps) >>/Users/jc/w/tmp/Tune-4088-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/abc/session/RoM/Golden_Slippers-G-32-4.abc/polka

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_40887.log 263256 Log file, useful mostly for debugging
Form_40885.log 866 Log file, useful mostly for debugging
Tune-4088-get.log 4089 Log file, useful mostly for debugging
Tune-4088-polka.abc 171 ABC music file with the extracted tune(s)
Tune-4088-polka.ps 6 PostScript
Tune-4088-polka.txt 171 Plain-text file with the extracted tune(s)
Tune-40884-get.log 3918 Log file, useful mostly for debugging
Tune-40888-get.log 6842 Log file, useful mostly for debugging
Tune-40889-get.log 3862 Log file, useful mostly for debugging
These files should be available for 24 hours.