Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/DftY/Thompson.abc/1767"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8311-1767.ps) >>/Users/jc/w/tmp/Tune-8311-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/DftY/Thompson.abc/1767

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_83112.log 461210 Log file, useful mostly for debugging
Coll_83115.log 437410 Log file, useful mostly for debugging
Form_83115.log 999 Log file, useful mostly for debugging
Tune-8311-1767.abc 150 ABC music file with the extracted tune(s)
Tune-8311-1767.ps 6 PostScript
Tune-8311-1767.txt 150 Plain-text file with the extracted tune(s)
Tune-8311-get.log 3946 Log file, useful mostly for debugging
Tune-83116-get.log 4429 Log file, useful mostly for debugging
These files should be available for 24 hours.