Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MM1/EliasHowe_MusiciansCompanionP3-1844-V2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6390-EliasHowe_MusiciansCompanionP3-1844-V2.ps) >>/Users/jc/w/tmp/Tune-6390-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MM1/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-6390-EliasHowe_MusiciansCompanionP3-1844-V2.abc 174 ABC music file with the extracted tune(s)
Tune-6390-EliasHowe_MusiciansCompanionP3-1844-V2.ps 6 PostScript
Tune-6390-EliasHowe_MusiciansCompanionP3-1844-V2.txt 174 Plain-text file with the extracted tune(s)
Tune-6390-get.log 4646 Log file, useful mostly for debugging
Tune-63900-get.log 8998 Log file, useful mostly for debugging
Tune-63901-get.log 3502 Log file, useful mostly for debugging
Tune-63903-ThomasBraysCountryDances1699.abc 164 ABC music file with the extracted tune(s)
Tune-63903-ThomasBraysCountryDances1699.ps 6 PostScript
Tune-63903-ThomasBraysCountryDances1699.txt 164 Plain-text file with the extracted tune(s)
Tune-63903-get.log 8872 Log file, useful mostly for debugging
Tune-63904-24CountryDances_1798_Preston.abc 164 ABC music file with the extracted tune(s)
Tune-63904-24CountryDances_1798_Preston.ps 6 PostScript
Tune-63904-24CountryDances_1798_Preston.txt 164 Plain-text file with the extracted tune(s)
Tune-63904-get.log 4482 Log file, useful mostly for debugging
Tune-63905-get.log 4612 Log file, useful mostly for debugging
Tune-63906-get.log 14502 Log file, useful mostly for debugging
These files should be available for 24 hours.