pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-29450-alfpolk.ps) >>/Users/jc/w/tmp/Tune-29450-get.log 2>&1" returned status 256
http://www.alfwarnock.info/alfs/abc/alfpolk.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-29450-alfpolk.abc 341 ABC music file with the extracted tune(s)
Tune-29450-alfpolk.ps 36475 PostScript
Tune-29450-alfpolk.txt 341 Plain-text file with the extracted tune(s)
Tune-29450-get.log 4248 Log file, useful mostly for debugging
These files should be available for 24 hours.