pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-89684-21421_MARQUIS_OF_WATERFORDS_HORNPIPE.ps) >>/Users/jc/w/tmp/Tune-89684-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/Kohlers/21421_MARQUIS_OF_WATERFORDS_HORNPIPE.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-89684-21421_MARQUIS_OF_WATERFORDS_HORNPIPE.abc 663 ABC music file with the extracted tune(s)
Tune-89684-21421_MARQUIS_OF_WATERFORDS_HORNPIPE.ps 39500 PostScript
Tune-89684-21421_MARQUIS_OF_WATERFORDS_HORNPIPE.txt 663 Plain-text file with the extracted tune(s)
Tune-89684-get.log 5111 Log file, useful mostly for debugging
These files should be available for 24 hours.