pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-19545-tb20.ps) >>/Users/jc/w/tmp/Tune-19545-get.log 2>&1" returned status 256
http://nigelgatherer.com/tunes/abc/tb20.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-19545-get.log 4315 Log file, useful mostly for debugging
Tune-19545-tb20.abc 306 ABC music file with the extracted tune(s)
Tune-19545-tb20.ps 36301 PostScript
Tune-19545-tb20.txt 306 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.