Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1801/SocialDances2002.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9331-SocialDances2002.ps) >>/Users/jc/w/tmp/Tune-9331-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1801/SocialDances2002.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-9331-SocialDances2002.abc 153 ABC music file with the extracted tune(s)
Tune-9331-SocialDances2002.ps 6 PostScript
Tune-9331-SocialDances2002.txt 153 Plain-text file with the extracted tune(s)
Tune-9331-get.log 4186 Log file, useful mostly for debugging
Tune-93312-blank.abc 140 ABC music file with the extracted tune(s)
Tune-93312-blank.pdf 2217 Portable Data Format
Tune-93312-blank.ps 6 PostScript
Tune-93312-blank.txt 140 Plain-text file with the extracted tune(s)
Tune-93312-get.log 4727 Log file, useful mostly for debugging
Tune-93313-get.log 4367 Log file, useful mostly for debugging
These files should be available for 24 hours.