Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1809/Playford_COST.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7995-Playford_COST.ps) >>/Users/jc/w/tmp/Tune-7995-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1809/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
Find_79959.log 1495 Log file, useful mostly for debugging
Tune-7995-Playford_COST.abc 150 ABC music file with the extracted tune(s)
Tune-7995-Playford_COST.ps 6 PostScript
Tune-7995-Playford_COST.txt 150 Plain-text file with the extracted tune(s)
Tune-7995-get.log 4129 Log file, useful mostly for debugging
Tune-79954-get.log 18981 Log file, useful mostly for debugging
Tune-79958-189_Vesper_Hymn-001.svg 21001 Scalable Vector Graphics format
Tune-79958-189_Vesper_Hymn.abc 1205 ABC music file with the extracted tune(s)
Tune-79958-189_Vesper_Hymn.txt 1205 Plain-text file with the extracted tune(s)
Tune-79958-get.log 4187 Log file, useful mostly for debugging
These files should be available for 24 hours.