Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Brodie/Straight_Skillern.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6431-Straight_Skillern.ps) >>/Users/jc/w/tmp/Tune-6431-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Brodie/Straight_Skillern.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_64318.log 639011 Log file, useful mostly for debugging
Coll_64319.log 139566 Log file, useful mostly for debugging
Tune-6431-Straight_Skillern.abc 156 ABC music file with the extracted tune(s)
Tune-6431-Straight_Skillern.ps 6 PostScript
Tune-6431-Straight_Skillern.txt 156 Plain-text file with the extracted tune(s)
Tune-6431-get.log 4221 Log file, useful mostly for debugging
Tune-64313-get.log 4153 Log file, useful mostly for debugging
Tune-64314-get.log 4324 Log file, useful mostly for debugging
Tune-64315-get.log 7591 Log file, useful mostly for debugging
Tune-64318-get.log 6037 Log file, useful mostly for debugging
Tune-64319-get.log 9011 Log file, useful mostly for debugging
These files should be available for 24 hours.