pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-74754-CR90.ps) >>/Users/jc/w/tmp/Tune-74754-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/Contra/CR90.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-74754-CR90.abc 1320 ABC music file with the extracted tune(s)
Tune-74754-CR90.ps 43366 PostScript
Tune-74754-CR90.txt 1320 Plain-text file with the extracted tune(s)
Tune-74754-get.log 4351 Log file, useful mostly for debugging
These files should be available for 24 hours.