pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-50163-11151_Air.ps) >>/Users/jc/w/tmp/Tune-50163-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/EliasHowe/MusiciansCompanionP1/11151_Air.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-50163-11151_Air.abc 1593 ABC music file with the extracted tune(s)
Tune-50163-11151_Air.ps 49919 PostScript
Tune-50163-11151_Air.txt 1593 Plain-text file with the extracted tune(s)
Tune-50163-get.log 200584 Log file, useful mostly for debugging
These files should be available for 24 hours.