Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Book07/Kerr_MM1-V1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4754-Kerr_MM1-V1.ps) >>/Users/jc/w/tmp/Tune-4754-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Book07/Kerr_MM1-V1.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_47547.log 661412 Log file, useful mostly for debugging
Tune-4754-Kerr_MM1-V1.abc 150 ABC music file with the extracted tune(s)
Tune-4754-Kerr_MM1-V1.ps 6 PostScript
Tune-4754-Kerr_MM1-V1.txt 150 Plain-text file with the extracted tune(s)
Tune-4754-get.log 4097 Log file, useful mostly for debugging
Tune-47541-get.log 3582 Log file, useful mostly for debugging
Tune-47542-get.log 4335 Log file, useful mostly for debugging
Tune-47543-get.log 4390 Log file, useful mostly for debugging
Tune-47544-get.log 2967 Log file, useful mostly for debugging
Tune-47545-get.log 3334 Log file, useful mostly for debugging
Tune-47549-Kohlers3.abc 148 ABC music file with the extracted tune(s)
Tune-47549-Kohlers3.txt 148 Plain-text file with the extracted tune(s)
Tune-47549-get.log 11796 Log file, useful mostly for debugging
These files should be available for 24 hours.