Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1818/dance.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1960-dance.ps) >>/Users/jc/w/tmp/Tune-1960-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1818/dance.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-1960-dance.abc 142 ABC music file with the extracted tune(s)
Tune-1960-dance.ps 6 PostScript
Tune-1960-dance.txt 142 Plain-text file with the extracted tune(s)
Tune-1960-get.log 3957 Log file, useful mostly for debugging
Tune-19602-get.log 3204 Log file, useful mostly for debugging
Tune-19603-CaledonianMusicalRepository_1811.abc 169 ABC music file with the extracted tune(s)
Tune-19603-CaledonianMusicalRepository_1811.ps 6 PostScript
Tune-19603-CaledonianMusicalRepository_1811.txt 169 Plain-text file with the extracted tune(s)
Tune-19603-get.log 8970 Log file, useful mostly for debugging
Tune-19604-endo.abc 141 ABC music file with the extracted tune(s)
Tune-19604-endo.ps 6 PostScript
Tune-19604-endo.txt 141 Plain-text file with the extracted tune(s)
Tune-19604-get.log 3865 Log file, useful mostly for debugging
Tune-19605-get.log 4380 Log file, useful mostly for debugging
These files should be available for 24 hours.