Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/MS/slurs.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-34490-slurs.ps) >>/Users/jc/w/tmp/Tune-34490-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/MS/slurs.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-34490-JohnnysGoneToFranceReel.abc 478 ABC music file with the extracted tune(s)
Tune-34490-JohnnysGoneToFranceReel.pdf 14848 Portable Data Format
Tune-34490-JohnnysGoneToFranceReel.ps 35697 PostScript
Tune-34490-JohnnysGoneToFranceReel.txt 478 Plain-text file with the extracted tune(s)
Tune-34490-get.log 9722 Log file, useful mostly for debugging
Tune-34490-slurs.abc 140 ABC music file with the extracted tune(s)
Tune-34490-slurs.ps 6 PostScript
Tune-34490-slurs.txt 140 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.