Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1767/Playford_AB.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8111-Playford_AB.ps) >>/Users/jc/w/tmp/Tune-8111-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1767/Playford_AB.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_81114.log 666491 Log file, useful mostly for debugging
Tune-8111-Playford_AB.abc 148 ABC music file with the extracted tune(s)
Tune-8111-Playford_AB.ps 6 PostScript
Tune-8111-Playford_AB.txt 148 Plain-text file with the extracted tune(s)
Tune-8111-get.log 4089 Log file, useful mostly for debugging
Tune-81116-Hamilton_HUTB2-1846-V1.abc 159 ABC music file with the extracted tune(s)
Tune-81116-Hamilton_HUTB2-1846-V1.ps 6 PostScript
Tune-81116-Hamilton_HUTB2-1846-V1.txt 159 Plain-text file with the extracted tune(s)
Tune-81116-get.log 4364 Log file, useful mostly for debugging
Tune-81117-get.log 3613 Log file, useful mostly for debugging
These files should be available for 24 hours.