pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-41377-Kerr_MM1-V1.ps) >>/Users/jc/w/tmp/Tune-41377-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Kerr/MM1/Kerr_MM1-V1.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-41377-Kerr_MM1-V1.abc 207926 ABC music file with the extracted tune(s)
Tune-41377-Kerr_MM1-V1.ps 2343958 PostScript
Tune-41377-Kerr_MM1-V1.txt 207926 Plain-text file with the extracted tune(s)
Tune-41377-get.log 268342 Log file, useful mostly for debugging
These files should be available for 24 hours.