pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-29794-MachineWithoutWheels.ps) >>/Users/jc/w/tmp/Tune-29794-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/Scotland/MachineWithoutWheels.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-29794-MachineWithoutWheels.abc 837 ABC music file with the extracted tune(s)
Tune-29794-MachineWithoutWheels.ps 36652 PostScript
Tune-29794-MachineWithoutWheels.txt 837 Plain-text file with the extracted tune(s)
Tune-29794-get.log 5080 Log file, useful mostly for debugging
These files should be available for 24 hours.