Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MM4/SCD_Book49-V2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7009-SCD_Book49-V2.ps) >>/Users/jc/w/tmp/Tune-7009-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MM4/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-7009-SCD_Book49-V2.abc 149 ABC music file with the extracted tune(s)
Tune-7009-SCD_Book49-V2.ps 6 PostScript
Tune-7009-SCD_Book49-V2.txt 149 Plain-text file with the extracted tune(s)
Tune-7009-get.log 4125 Log file, useful mostly for debugging
Tune-70092-get.log 4577 Log file, useful mostly for debugging
Tune-70094-get.log 6109 Log file, useful mostly for debugging
Tune-70095-get.log 5519 Log file, useful mostly for debugging
Tune-70096-Gow-CSR2-abc1.abc 150 ABC music file with the extracted tune(s)
Tune-70096-Gow-CSR2-abc1.txt 150 Plain-text file with the extracted tune(s)
Tune-70096-get.log 3240 Log file, useful mostly for debugging
These files should be available for 24 hours.