Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/JamesOswald/CPC/21561_Benney_Side.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1912-all.ps) >>/Users/jc/w/tmp/Tune-1912-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/JamesOswald/CPC/21561_Benney_Side.abc/all

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_19122.log 261851 Log file, useful mostly for debugging
Coll_19126.log 263256 Log file, useful mostly for debugging
Coll_19127.log 136999 Log file, useful mostly for debugging
Form_19127.log 834 Log file, useful mostly for debugging
Tune-1912-all.abc 169 ABC music file with the extracted tune(s)
Tune-1912-all.ps 6 PostScript
Tune-1912-all.txt 169 Plain-text file with the extracted tune(s)
Tune-1912-get.log 4047 Log file, useful mostly for debugging
Tune-19123-get.log 6050 Log file, useful mostly for debugging
Tune-19128-32581_RONDO_OR_APE_SHENKIN.abc 2200 ABC music file with the extracted tune(s)
Tune-19128-32581_RONDO_OR_APE_SHENKIN.ps 68319 PostScript
Tune-19128-32581_RONDO_OR_APE_SHENKIN.txt 2200 Plain-text file with the extracted tune(s)
Tune-19128-get.log 10629 Log file, useful mostly for debugging
These files should be available for 24 hours.