Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/abc/session/RoM/Colemans_March-D-32-2.abc/march"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-64984-march.ps) >>/Users/jc/w/tmp/Tune-64984-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/abc/session/RoM/Colemans_March-D-32-2.abc/march

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_64984.log 264661 Log file, useful mostly for debugging
Tune-64984-get.log 4098 Log file, useful mostly for debugging
Tune-64984-march.abc 170 ABC music file with the extracted tune(s)
Tune-64984-march.ps 6 PostScript
Tune-64984-march.txt 170 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.