Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/JamesOswald/CPC/15271_Murrays_March.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9434-all.ps) >>/Users/jc/w/tmp/Tune-9434-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/JamesOswald/CPC/15271_Murrays_March.abc/all

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.65 512x512 PNG]
filesizedescription
Coll_94349.log 882846 Log file, useful mostly for debugging
Tune-9434-all.abc 171 ABC music file with the extracted tune(s)
Tune-9434-all.ps 6 PostScript
Tune-9434-all.txt 171 Plain-text file with the extracted tune(s)
Tune-9434-get.log 4053 Log file, useful mostly for debugging
Tune-94347-30461_Red_Lion_Hornpipe.abc 1295 ABC music file with the extracted tune(s)
Tune-94347-30461_Red_Lion_Hornpipe.ps 43095 PostScript
Tune-94347-30461_Red_Lion_Hornpipe.txt 1295 Plain-text file with the extracted tune(s)
Tune-94347-get.log 5047 Log file, useful mostly for debugging
These files should be available for 24 hours.