Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Roy_Goldring/MMM2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-5068-MMM2.ps) >>/Users/jc/w/tmp/Tune-5068-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Roy_Goldring/MMM2.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_5068.log 280115 Log file, useful mostly for debugging
Coll_50682.log 95366 Log file, useful mostly for debugging
Find_50686.log 1797 Log file, useful mostly for debugging
Find_50689.log 1687 Log file, useful mostly for debugging
Site50684.log 194 Log file, useful mostly for debugging
Tune-5068-MMM2.abc 149 ABC music file with the extracted tune(s)
Tune-5068-MMM2.ps 6 PostScript
Tune-5068-MMM2.txt 149 Plain-text file with the extracted tune(s)
Tune-5068-get.log 9357 Log file, useful mostly for debugging
Tune-50683-get.log 5452 Log file, useful mostly for debugging
Tune-50687-get.log 5581 Log file, useful mostly for debugging
These files should be available for 24 hours.