Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/slide/JohnWalsh.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2811-JohnWalsh.ps) >>/Users/jc/w/tmp/Tune-2811-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/slide/JohnWalsh.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-2811-JohnWalsh.abc 147 ABC music file with the extracted tune(s)
Tune-2811-JohnWalsh.ps 6 PostScript
Tune-2811-JohnWalsh.txt 147 Plain-text file with the extracted tune(s)
Tune-2811-get.log 4051 Log file, useful mostly for debugging
Tune-28114-DanielWright_ECPMH.abc 155 ABC music file with the extracted tune(s)
Tune-28114-DanielWright_ECPMH.ps 6 PostScript
Tune-28114-DanielWright_ECPMH.txt 155 Plain-text file with the extracted tune(s)
Tune-28114-get.log 4161 Log file, useful mostly for debugging
Tune-28115-24CountryDances_1808_Goulding_FTM.abc 169 ABC music file with the extracted tune(s)
Tune-28115-24CountryDances_1808_Goulding_FTM.ps 6 PostScript
Tune-28115-24CountryDances_1808_Goulding_FTM.txt 169 Plain-text file with the extracted tune(s)
Tune-28115-get.log 4468 Log file, useful mostly for debugging
These files should be available for 24 hours.