pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-21672-493_LADY_GRACE_STEWART.ps) >>/Users/jc/w/tmp/Tune-21672-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/SCD/Glen2/493_LADY_GRACE_STEWART.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-21672-493_LADY_GRACE_STEWART.abc 843 ABC music file with the extracted tune(s)
Tune-21672-493_LADY_GRACE_STEWART.ps 38379 PostScript
Tune-21672-493_LADY_GRACE_STEWART.txt 843 Plain-text file with the extracted tune(s)
Tune-21672-get.log 5291 Log file, useful mostly for debugging
These files should be available for 24 hours.