Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Kerr_MM/endo.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7286-endo.ps) >>/Users/jc/w/tmp/Tune-7286-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Kerr_MM/endo.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_72865.log 288545 Log file, useful mostly for debugging
Coll_72866.log 557420 Log file, useful mostly for debugging
Coll_72868.log 284330 Log file, useful mostly for debugging
Tune-7286-endo.abc 144 ABC music file with the extracted tune(s)
Tune-7286-endo.ps 6 PostScript
Tune-7286-endo.txt 144 Plain-text file with the extracted tune(s)
Tune-7286-get.log 3956 Log file, useful mostly for debugging
Tune-72861-get.log 4038 Log file, useful mostly for debugging
Tune-72862-get.log 1293 Log file, useful mostly for debugging
Tune-72866-get.log 5292 Log file, useful mostly for debugging
Tune-72869-get.log 1383 Log file, useful mostly for debugging
These files should be available for 24 hours.