Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/JamesOswald/CPC/13091_the_14th_of_October.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9645-all.ps) >>/Users/jc/w/tmp/Tune-9645-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/JamesOswald/CPC/13091_the_14th_of_October.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
Tune-9645-all.abc 177 ABC music file with the extracted tune(s)
Tune-9645-all.ps 6 PostScript
Tune-9645-all.txt 177 Plain-text file with the extracted tune(s)
Tune-9645-get.log 4093 Log file, useful mostly for debugging
Tune-96450-043_SallyKelly.abc 659 ABC music file with the extracted tune(s)
Tune-96450-043_SallyKelly.gif 0 Graphics Interchange Format, the proprietary scan-line picture format
Tune-96450-043_SallyKelly.ps 34948 PostScript
Tune-96450-043_SallyKelly.txt 659 Plain-text file with the extracted tune(s)
Tune-96450-get.log 5400 Log file, useful mostly for debugging
Tune-96455-get.log 4914 Log file, useful mostly for debugging
These files should be available for 24 hours.