Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1799/tune.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2154-tune.ps) >>/Users/jc/w/tmp/Tune-2154-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1799/tune.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_21546.log 416400 Log file, useful mostly for debugging
Coll_21547.log 275900 Log file, useful mostly for debugging
Tune-2154-get.log 3942 Log file, useful mostly for debugging
Tune-2154-tune.abc 141 ABC music file with the extracted tune(s)
Tune-2154-tune.ps 6 PostScript
Tune-2154-tune.txt 141 Plain-text file with the extracted tune(s)
Tune-21546-CJSurtees.abc 146 ABC music file with the extracted tune(s)
Tune-21546-CJSurtees.ps 6 PostScript
Tune-21546-CJSurtees.txt 146 Plain-text file with the extracted tune(s)
Tune-21546-get.log 4089 Log file, useful mostly for debugging
Tune-21549-get.log 6245 Log file, useful mostly for debugging
These files should be available for 24 hours.