Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1748/LondonMagazine.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8365-LondonMagazine.ps) >>/Users/jc/w/tmp/Tune-8365-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1748/LondonMagazine.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_83655.log 277812 Log file, useful mostly for debugging
Coll_83658.log 284812 Log file, useful mostly for debugging
Tune-8365-LondonMagazine.abc 151 ABC music file with the extracted tune(s)
Tune-8365-LondonMagazine.ps 6 PostScript
Tune-8365-LondonMagazine.txt 151 Plain-text file with the extracted tune(s)
Tune-8365-get.log 4146 Log file, useful mostly for debugging
Tune-83650-get.log 4358 Log file, useful mostly for debugging
Tune-83651-get.log 11862 Log file, useful mostly for debugging
Tune-83652-get.log 9838 Log file, useful mostly for debugging
Tune-83653-get.log 4308 Log file, useful mostly for debugging
Tune-83654-get.log 4390 Log file, useful mostly for debugging
Tune-83656-get.log 4941 Log file, useful mostly for debugging
Tune-83657-get.log 3454 Log file, useful mostly for debugging
Tune-83658-get.log 13226 Log file, useful mostly for debugging
These files should be available for 24 hours.