Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/CDM5/Nelson.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6535-Nelson.ps) >>/Users/jc/w/tmp/Tune-6535-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/CDM5/Nelson.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-6535-MuckinOGeordiesByre.abc 506 ABC music file with the extracted tune(s)
Tune-6535-MuckinOGeordiesByre.gif 0 Graphics Interchange Format, the proprietary scan-line picture format
Tune-6535-MuckinOGeordiesByre.ps 34303 PostScript
Tune-6535-MuckinOGeordiesByre.txt 506 Plain-text file with the extracted tune(s)
Tune-6535-Nelson.abc 143 ABC music file with the extracted tune(s)
Tune-6535-Nelson.ps 6 PostScript
Tune-6535-Nelson.txt 143 Plain-text file with the extracted tune(s)
Tune-6535-get.log 9403 Log file, useful mostly for debugging
Tune-65351-get.log 4492 Log file, useful mostly for debugging
Tune-65353-get.log 4702 Log file, useful mostly for debugging
Tune-65355-get.log 22335 Log file, useful mostly for debugging
Tune-65357-get.log 2972 Log file, useful mostly for debugging
Tune-65358-alltunes.abc 8302 ABC music file with the extracted tune(s)
Tune-65358-alltunes.txt 8302 Plain-text file with the extracted tune(s)
Tune-65358-get.log 13823 Log file, useful mostly for debugging
These files should be available for 24 hours.