Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/oneills/1850/X/1518_jw.abc"
X:1518 not found in http://john-chambers.us/~jc/music/book/oneills/1850/X/1518_jw.abc
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9716-1518_jw.ps) >>/Users/jc/w/tmp/Tune-9716-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/oneills/1850/X/1518_jw.abc

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 PNG]
filesizedescription
Coll_97163.log 136757 Log file, useful mostly for debugging
Form_97164.log 880 Log file, useful mostly for debugging
Tune-9716-1518_jw.abc 0 ABC music file with the extracted tune(s)
Tune-9716-1518_jw.ps 6 PostScript
Tune-9716-1518_jw.txt 0 Plain-text file with the extracted tune(s)
Tune-9716-get.log 4510 Log file, useful mostly for debugging
These files should be available for 24 hours.