Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1804/dance.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4830-dance.ps) >>/Users/jc/w/tmp/Tune-4830-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1804/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-4830-dance.abc 142 ABC music file with the extracted tune(s)
Tune-4830-dance.ps 6 PostScript
Tune-4830-dance.txt 142 Plain-text file with the extracted tune(s)
Tune-4830-get.log 3959 Log file, useful mostly for debugging
Tune-48300-get.log 14142 Log file, useful mostly for debugging
Tune-48301-get.log 10229 Log file, useful mostly for debugging
Tune-48307-EliasHowe_MusiciansCompanionP2-1843-V2.abc 174 ABC music file with the extracted tune(s)
Tune-48307-EliasHowe_MusiciansCompanionP2-1843-V2.txt 174 Plain-text file with the extracted tune(s)
Tune-48307-get.log 3684 Log file, useful mostly for debugging
Tune-48309-get.log 5228 Log file, useful mostly for debugging
These files should be available for 24 hours.