Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Book39/SCD_Book49-V2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2708-SCD_Book49-V2.ps) >>/Users/jc/w/tmp/Tune-2708-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Book39/SCD_Book49-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-2708-SCD_Book49-V2.abc 152 ABC music file with the extracted tune(s)
Tune-2708-SCD_Book49-V2.ps 6 PostScript
Tune-2708-SCD_Book49-V2.txt 152 Plain-text file with the extracted tune(s)
Tune-2708-get.log 4141 Log file, useful mostly for debugging
Tune-27082-get.log 8583 Log file, useful mostly for debugging
Tune-27083-get.log 5566 Log file, useful mostly for debugging
Tune-27084-get.log 4099 Log file, useful mostly for debugging
Tune-27086-get.log 5413 Log file, useful mostly for debugging
Tune-27087-get.log 5541 Log file, useful mostly for debugging
Tune-27089-get.log 3280 Log file, useful mostly for debugging
These files should be available for 24 hours.