Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/cache/Tune-13358-Papirossen_Em.abc/tmp"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2277-tmp.ps) >>/Users/jc/w/tmp/Tune-2277-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/cache/Tune-13358-Papirossen_Em.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_2277.log 273610 Log file, useful mostly for debugging
Coll_22771.log 282010 Log file, useful mostly for debugging
Coll_22777.log 270809 Log file, useful mostly for debugging
Form_22770.log 1149 Log file, useful mostly for debugging
Form_22771.log 1009 Log file, useful mostly for debugging
Form_22775.log 852 Log file, useful mostly for debugging
Form_22777.log 950 Log file, useful mostly for debugging
Tune-2277-get.log 4027 Log file, useful mostly for debugging
Tune-2277-tmp.abc 166 ABC music file with the extracted tune(s)
Tune-2277-tmp.ps 6 PostScript
Tune-2277-tmp.txt 166 Plain-text file with the extracted tune(s)
Tune-22770-get.log 5103 Log file, useful mostly for debugging
Tune-22771-get.log 5470 Log file, useful mostly for debugging
Tune-22773-get.log 12186 Log file, useful mostly for debugging
Tune-22774-get.log 8664 Log file, useful mostly for debugging
Tune-22776-get.log 4575 Log file, useful mostly for debugging
Tune-22777-get.log 3423 Log file, useful mostly for debugging
Tune-22778-get.log 3362 Log file, useful mostly for debugging
These files should be available for 24 hours.