Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1796/Kerr_MM3-V2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9791-Kerr_MM3-V2.ps) >>/Users/jc/w/tmp/Tune-9791-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1796/Kerr_MM3-V2.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_97918.log 278710 Log file, useful mostly for debugging
Tune-9791-Kerr_MM3-V2.abc 148 ABC music file with the extracted tune(s)
Tune-9791-Kerr_MM3-V2.ps 6 PostScript
Tune-9791-Kerr_MM3-V2.txt 148 Plain-text file with the extracted tune(s)
Tune-9791-get.log 4087 Log file, useful mostly for debugging
Tune-97910-blank.abc 141 ABC music file with the extracted tune(s)
Tune-97910-blank.ps 6 PostScript
Tune-97910-blank.txt 141 Plain-text file with the extracted tune(s)
Tune-97910-get.log 5328 Log file, useful mostly for debugging
Tune-97914-get.log 1327 Log file, useful mostly for debugging
Tune-97918-get.log 5324 Log file, useful mostly for debugging
Tune-97918-sett.abc 141 ABC music file with the extracted tune(s)
Tune-97918-sett.ps 6 PostScript
Tune-97918-sett.txt 141 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.