pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-55520-SweetMaidOfGlendaruel.ps) >>/Users/jc/w/tmp/Tune-55520-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/src/jcabc2ps-20150117/abc/SweetMaidOfGlendaruel.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
Tune-55520-SweetMaidOfGlendaruel.abc 602 ABC music file with the extracted tune(s)
Tune-55520-SweetMaidOfGlendaruel.ps 34950 PostScript
Tune-55520-SweetMaidOfGlendaruel.txt 602 Plain-text file with the extracted tune(s)
Tune-55520-get.log 5315 Log file, useful mostly for debugging
These files should be available for 24 hours.