Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/cache/Tune-36318-GoldenBookOfFavoriteSongs2.abc/tmp"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8708-tmp.ps) >>/Users/jc/w/tmp/Tune-8708-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/cache/Tune-36318-GoldenBookOfFavoriteSongs2.abc/tmp

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_87085.log 270808 Log file, useful mostly for debugging
Coll_87087.log 851631 Log file, useful mostly for debugging
Form_87081.log 942 Log file, useful mostly for debugging
Tune-8708-get.log 4109 Log file, useful mostly for debugging
Tune-8708-tmp.abc 179 ABC music file with the extracted tune(s)
Tune-8708-tmp.ps 6 PostScript
Tune-8708-tmp.txt 179 Plain-text file with the extracted tune(s)
Tune-87081-get.log 180205 Log file, useful mostly for debugging
Tune-87083-get.log 5791 Log file, useful mostly for debugging
Tune-87084-get.log 4991 Log file, useful mostly for debugging
Tune-87087-get.log 185710 Log file, useful mostly for debugging
Tune-87089-get.log 0 Log file, useful mostly for debugging
These files should be available for 24 hours.