Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/3D2006/book_of_rights.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1731-book_of_rights.ps) >>/Users/jc/w/tmp/Tune-1731-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/3D2006/book_of_rights.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_1731.log 149253 Log file, useful mostly for debugging
Coll_17319.log 579900 Log file, useful mostly for debugging
Form_17310.log 877 Log file, useful mostly for debugging
Tune-1731-book_of_rights.abc 153 ABC music file with the extracted tune(s)
Tune-1731-book_of_rights.ps 6 PostScript
Tune-1731-book_of_rights.txt 153 Plain-text file with the extracted tune(s)
Tune-1731-get.log 4162 Log file, useful mostly for debugging
Tune-17310-get.log 5855 Log file, useful mostly for debugging
Tune-17315-get.log 10637 Log file, useful mostly for debugging
Tune-17316-get.log 5414 Log file, useful mostly for debugging
These files should be available for 24 hours.