Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Book21/Playford_COST.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2138-Playford_COST.ps) >>/Users/jc/w/tmp/Tune-2138-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Book21/Playford_COST.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-2138-Playford_COST.abc 152 ABC music file with the extracted tune(s)
Tune-2138-Playford_COST.ps 6 PostScript
Tune-2138-Playford_COST.txt 152 Plain-text file with the extracted tune(s)
Tune-2138-get.log 4139 Log file, useful mostly for debugging
Tune-21381-get.log 1383 Log file, useful mostly for debugging
Tune-21383-_.abc 144 ABC music file with the extracted tune(s)
Tune-21383-_.txt 144 Plain-text file with the extracted tune(s)
Tune-21383-get.log 3060 Log file, useful mostly for debugging
Tune-21384-_.abc 146 ABC music file with the extracted tune(s)
Tune-21384-_.txt 146 Plain-text file with the extracted tune(s)
Tune-21384-get.log 3072 Log file, useful mostly for debugging
Tune-21386-get.log 3291 Log file, useful mostly for debugging
These files should be available for 24 hours.