pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-29758-232_LeiutColIbbetsonsQuickMarch.ps) >>/Users/jc/w/tmp/Tune-29758-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/AbrahamMackintosh/232_LeiutColIbbetsonsQuickMarch.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-29758-232_LeiutColIbbetsonsQuickMarch.abc 892 ABC music file with the extracted tune(s)
Tune-29758-232_LeiutColIbbetsonsQuickMarch.ps 38307 PostScript
Tune-29758-232_LeiutColIbbetsonsQuickMarch.txt 892 Plain-text file with the extracted tune(s)
Tune-29758-get.log 5084 Log file, useful mostly for debugging
These files should be available for 24 hours.