Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Whetherly09/IaST-abc1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8600-IaST-abc1.ps) >>/Users/jc/w/tmp/Tune-8600-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Whetherly09/IaST-abc1.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-8600-IaST-abc1.abc 153 ABC music file with the extracted tune(s)
Tune-8600-IaST-abc1.ps 6 PostScript
Tune-8600-IaST-abc1.txt 153 Plain-text file with the extracted tune(s)
Tune-8600-get.log 11580 Log file, useful mostly for debugging
Tune-86000-get.log 1685 Log file, useful mostly for debugging
Tune-86001-get.log 3998 Log file, useful mostly for debugging
Tune-86002-get.log 4360 Log file, useful mostly for debugging
Tune-86004-get.log 9674 Log file, useful mostly for debugging
Tune-86006-get.log 4700 Log file, useful mostly for debugging
These files should be available for 24 hours.