pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8452-J_B_Milne.ps) >>/Users/jc/w/tmp/Tune-8452-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/Square/J_B_Milne.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_84520.log 674920 Log file, useful mostly for debugging
Coll_84524.log 863710 Log file, useful mostly for debugging
Tune-8452-J_B_Milne.abc 700 ABC music file with the extracted tune(s)
Tune-8452-J_B_Milne.ps 37015 PostScript
Tune-8452-J_B_Milne.txt 700 Plain-text file with the extracted tune(s)
Tune-8452-get.log 9538 Log file, useful mostly for debugging
Tune-84526-ViolaRuth_AmericanSD.abc 8423 ABC music file with the extracted tune(s)
Tune-84526-ViolaRuth_AmericanSD.pdf 139360 Portable Data Format
Tune-84526-ViolaRuth_AmericanSD.ps 111400 PostScript
Tune-84526-ViolaRuth_AmericanSD.txt 8423 Plain-text file with the extracted tune(s)
Tune-84526-get.log 12561 Log file, useful mostly for debugging
These files should be available for 24 hours.