Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/CPC/Kohlers1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-3500-Kohlers1.ps) >>/Users/jc/w/tmp/Tune-3500-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/CPC/Kohlers1.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-3500-Kohlers1.abc 144 ABC music file with the extracted tune(s)
Tune-3500-Kohlers1.ps 6 PostScript
Tune-3500-Kohlers1.txt 144 Plain-text file with the extracted tune(s)
Tune-3500-get.log 4016 Log file, useful mostly for debugging
Tune-35001-book_of_rights.abc 155 ABC music file with the extracted tune(s)
Tune-35001-book_of_rights.pdf 2217 Portable Data Format
Tune-35001-book_of_rights.ps 6 PostScript
Tune-35001-book_of_rights.txt 155 Plain-text file with the extracted tune(s)
Tune-35001-get.log 5026 Log file, useful mostly for debugging
Tune-35002-get.log 8713 Log file, useful mostly for debugging
Tune-35003-dim.abc 146 ABC music file with the extracted tune(s)
Tune-35003-dim.ps 6 PostScript
Tune-35003-dim.txt 146 Plain-text file with the extracted tune(s)
Tune-35003-get.log 4005 Log file, useful mostly for debugging
Tune-35004-JohnTreat_GftF2.abc 156 ABC music file with the extracted tune(s)
Tune-35004-JohnTreat_GftF2.ps 6 PostScript
Tune-35004-JohnTreat_GftF2.txt 156 Plain-text file with the extracted tune(s)
Tune-35004-get.log 4245 Log file, useful mostly for debugging
Tune-35009-MMM2.abc 147 ABC music file with the extracted tune(s)
Tune-35009-MMM2.pdf 2217 Portable Data Format
Tune-35009-MMM2.ps 6 PostScript
Tune-35009-MMM2.txt 147 Plain-text file with the extracted tune(s)
Tune-35009-get.log 4748 Log file, useful mostly for debugging
These files should be available for 24 hours.