Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/cache/BB50.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6834-BB50.ps) >>/Users/jc/w/tmp/Tune-6834-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/cache/BB50.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Form_68343.log 930 Log file, useful mostly for debugging
Tune-6834-BB50.abc 142 ABC music file with the extracted tune(s)
Tune-6834-BB50.ps 6 PostScript
Tune-6834-BB50.txt 142 Plain-text file with the extracted tune(s)
Tune-6834-get.log 3942 Log file, useful mostly for debugging
Tune-68340-get.log 5318 Log file, useful mostly for debugging
Tune-68341-Button_Whitaker_12ElegantNewDances_1810.abc 176 ABC music file with the extracted tune(s)
Tune-68341-Button_Whitaker_12ElegantNewDances_1810.ps 6 PostScript
Tune-68341-Button_Whitaker_12ElegantNewDances_1810.txt 176 Plain-text file with the extracted tune(s)
Tune-68341-get.log 4719 Log file, useful mostly for debugging
These files should be available for 24 hours.