Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MM1/_.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1230-_.ps) >>/Users/jc/w/tmp/Tune-1230-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MM1/_.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Tune-1230-_.abc 137 ABC music file with the extracted tune(s)
Tune-1230-_.ps 6 PostScript
Tune-1230-_.txt 137 Plain-text file with the extracted tune(s)
Tune-1230-get.log 3873 Log file, useful mostly for debugging
Tune-12308-12SelectedCountryDances_1772_Rutherford.abc 176 ABC music file with the extracted tune(s)
Tune-12308-12SelectedCountryDances_1772_Rutherford.pdf 2217 Portable Data Format
Tune-12308-12SelectedCountryDances_1772_Rutherford.ps 6 PostScript
Tune-12308-12SelectedCountryDances_1772_Rutherford.txt 176 Plain-text file with the extracted tune(s)
Tune-12308-get.log 5721 Log file, useful mostly for debugging
These files should be available for 24 hours.