Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1765/SocialDances2002.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-5339-SocialDances2002.ps) >>/Users/jc/w/tmp/Tune-5339-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1765/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-5339-SocialDances2002.abc 153 ABC music file with the extracted tune(s)
Tune-5339-SocialDances2002.ps 6 PostScript
Tune-5339-SocialDances2002.txt 153 Plain-text file with the extracted tune(s)
Tune-5339-get.log 4190 Log file, useful mostly for debugging
Tune-53390-MansellThe_PLFD1701_454.abc 398 ABC music file with the extracted tune(s)
Tune-53390-MansellThe_PLFD1701_454.gif 0 Graphics Interchange Format, the proprietary scan-line picture format
Tune-53390-MansellThe_PLFD1701_454.ps 34891 PostScript
Tune-53390-MansellThe_PLFD1701_454.txt 398 Plain-text file with the extracted tune(s)
Tune-53390-get.log 5586 Log file, useful mostly for debugging
Tune-53391-get.log 119891 Log file, useful mostly for debugging
Tune-53395-get.log 5528 Log file, useful mostly for debugging
These files should be available for 24 hours.