pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-39821-20252_American_March.ps) >>/Users/jc/w/tmp/Tune-39821-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/EliasHowe/MusiciansCompanionP2/20252_American_March.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-39821-20252_American_March.abc 684 ABC music file with the extracted tune(s)
Tune-39821-20252_American_March.ps 35812 PostScript
Tune-39821-20252_American_March.txt 684 Plain-text file with the extracted tune(s)
Tune-39821-ViolaRuth_AmericanSD.abc 157 ABC music file with the extracted tune(s)
Tune-39821-ViolaRuth_AmericanSD.pdf 2217 Portable Data Format
Tune-39821-ViolaRuth_AmericanSD.ps 6 PostScript
Tune-39821-ViolaRuth_AmericanSD.txt 157 Plain-text file with the extracted tune(s)
Tune-39821-get.log 10106 Log file, useful mostly for debugging
These files should be available for 24 hours.