Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/dup/BB50.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7519-BB50.ps) >>/Users/jc/w/tmp/Tune-7519-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/dup/BB50.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_75199.log 480812 Log file, useful mostly for debugging
Tune-7519-BB50.abc 140 ABC music file with the extracted tune(s)
Tune-7519-BB50.ps 6 PostScript
Tune-7519-BB50.txt 140 Plain-text file with the extracted tune(s)
Tune-7519-get.log 3936 Log file, useful mostly for debugging
Tune-75191-get.log 1390 Log file, useful mostly for debugging
Tune-75195-get.log 1379 Log file, useful mostly for debugging
Tune-75199-get.log 5063 Log file, useful mostly for debugging
These files should be available for 24 hours.