pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-44272-WHEN_THE_SAINTS_GO_MARCHING_IN_SAINTMAR_2.ps) >>/Users/jc/w/tmp/Tune-44272-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/mirror/corneymusers/WHEN_THE_SAINTS_GO_MARCHING_IN_SAINTMAR_2.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-44272-WHEN_THE_SAINTS_GO_MARCHING_IN_SAINTMAR_2.abc 570 ABC music file with the extracted tune(s)
Tune-44272-WHEN_THE_SAINTS_GO_MARCHING_IN_SAINTMAR_2.ps 38552 PostScript
Tune-44272-WHEN_THE_SAINTS_GO_MARCHING_IN_SAINTMAR_2.txt 570 Plain-text file with the extracted tune(s)
Tune-44272-get.log 5870 Log file, useful mostly for debugging
These files should be available for 24 hours.