Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/GlendarrochSDS/CSGBT_1794-V1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6853-CSGBT_1794-V1.ps) >>/Users/jc/w/tmp/Tune-6853-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/GlendarrochSDS/CSGBT_1794-V1.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_68533.log 1189851 Log file, useful mostly for debugging
Coll_68538.log 568660 Log file, useful mostly for debugging
Tune-6853-CSGBT_1794-V1.abc 160 ABC music file with the extracted tune(s)
Tune-6853-CSGBT_1794-V1.ps 6 PostScript
Tune-6853-CSGBT_1794-V1.txt 160 Plain-text file with the extracted tune(s)
Tune-6853-get.log 9042 Log file, useful mostly for debugging
Tune-68536-get.log 4272 Log file, useful mostly for debugging
These files should be available for 24 hours.