Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/CNS/Tune-97455-tmp.abc/tmp"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7831-tmp.ps) >>/Users/jc/w/tmp/Tune-7831-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/CNS/Tune-97455-tmp.abc/tmp

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_78310.log 1558561 Log file, useful mostly for debugging
Coll_78313.log 2851282 Log file, useful mostly for debugging
Coll_78315.log 1613027 Log file, useful mostly for debugging
Tune-7831-get.log 3987 Log file, useful mostly for debugging
Tune-7831-tmp.abc 154 ABC music file with the extracted tune(s)
Tune-7831-tmp.ps 6 PostScript
Tune-7831-tmp.txt 154 Plain-text file with the extracted tune(s)
Tune-78310-get.log 5306 Log file, useful mostly for debugging
Tune-78311-get.log 15048 Log file, useful mostly for debugging
Tune-78314-get.log 20505 Log file, useful mostly for debugging
Tune-78316-get.log 4313 Log file, useful mostly for debugging
Tune-78317-get.log 4173 Log file, useful mostly for debugging
Tune-78319-ChristiesStr.abc 176 ABC music file with the extracted tune(s)
Tune-78319-ChristiesStr.ps 6 PostScript
Tune-78319-ChristiesStr.txt 176 Plain-text file with the extracted tune(s)
Tune-78319-get.log 16312 Log file, useful mostly for debugging
These files should be available for 24 hours.