Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MM4/EliasHowe_MusiciansCompanionP3-1844-V2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6503-EliasHowe_MusiciansCompanionP3-1844-V2.ps) >>/Users/jc/w/tmp/Tune-6503-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MM4/EliasHowe_MusiciansCompanionP3-1844-V2.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-6503-EliasHowe_MusiciansCompanionP3-1844-V2.abc 174 ABC music file with the extracted tune(s)
Tune-6503-EliasHowe_MusiciansCompanionP3-1844-V2.ps 6 PostScript
Tune-6503-EliasHowe_MusiciansCompanionP3-1844-V2.txt 174 Plain-text file with the extracted tune(s)
Tune-6503-get.log 4646 Log file, useful mostly for debugging
Tune-65030-get.log 4436 Log file, useful mostly for debugging
Tune-65031-get.log 8494 Log file, useful mostly for debugging
Tune-65032-get.log 9563 Log file, useful mostly for debugging
Tune-65033-Wilson_Harmony_4NCD_1812_V2.abc 164 ABC music file with the extracted tune(s)
Tune-65033-Wilson_Harmony_4NCD_1812_V2.ps 6 PostScript
Tune-65033-Wilson_Harmony_4NCD_1812_V2.txt 164 Plain-text file with the extracted tune(s)
Tune-65033-get.log 20346 Log file, useful mostly for debugging
Tune-65035-get.log 3522 Log file, useful mostly for debugging
Tune-65036-get.log 3586 Log file, useful mostly for debugging
Tune-65037-get.log 8345 Log file, useful mostly for debugging
These files should be available for 24 hours.