pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-59628-136001_the_Tenpenny_Bit.ps) >>/Users/jc/w/tmp/Tune-59628-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Kerr/MM1/136001_the_Tenpenny_Bit.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-59628-136001_the_Tenpenny_Bit.abc 460 ABC music file with the extracted tune(s)
Tune-59628-136001_the_Tenpenny_Bit.ps 34220 PostScript
Tune-59628-136001_the_Tenpenny_Bit.txt 460 Plain-text file with the extracted tune(s)
Tune-59628-get.log 4768 Log file, useful mostly for debugging
These files should be available for 24 hours.