Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/cache/Tune-24818-IgnatiusSancho_CNS_v2.abc/tmp"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4174-tmp.ps) >>/Users/jc/w/tmp/Tune-4174-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/cache/Tune-24818-IgnatiusSancho_CNS_v2.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_41740.log 620681 Log file, useful mostly for debugging
Coll_41743.log 1594849 Log file, useful mostly for debugging
Coll_41744.log 275009 Log file, useful mostly for debugging
Coll_41749.log 623541 Log file, useful mostly for debugging
Form_4174.log 851 Log file, useful mostly for debugging
Form_41740.log 1181 Log file, useful mostly for debugging
Form_41742.log 1011 Log file, useful mostly for debugging
Form_41745.log 876 Log file, useful mostly for debugging
Form_41748.log 879 Log file, useful mostly for debugging
Tune-4174-get.log 4079 Log file, useful mostly for debugging
Tune-4174-tmp.abc 174 ABC music file with the extracted tune(s)
Tune-4174-tmp.ps 6 PostScript
Tune-4174-tmp.txt 174 Plain-text file with the extracted tune(s)
Tune-41740-get.log 5695 Log file, useful mostly for debugging
Tune-41746-get.log 50855 Log file, useful mostly for debugging
Tune-41747-get.log 48900 Log file, useful mostly for debugging
Tune-41749-get.log 18831 Log file, useful mostly for debugging
These files should be available for 24 hours.