pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-92397-20593_Constitution.ps) >>/Users/jc/w/tmp/Tune-92397-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/EliasHowe/MusiciansCompanionP2/20593_Constitution.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-92397-20593_Constitution.abc 654 ABC music file with the extracted tune(s)
Tune-92397-20593_Constitution.ps 35430 PostScript
Tune-92397-20593_Constitution.txt 654 Plain-text file with the extracted tune(s)
Tune-92397-get.log 8063 Log file, useful mostly for debugging
These files should be available for 24 hours.