pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-37649-_Thompsons_V4_1773-1780_PD.ps) >>/Users/jc/w/tmp/Tune-37649-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Thompson/_Thompsons_V4_1773-1780_PD.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
Form_37649.log 908 Log file, useful mostly for debugging
Tune-37649-_Thompsons_V4_1773-1780_PD.abc 455 ABC music file with the extracted tune(s)
Tune-37649-_Thompsons_V4_1773-1780_PD.ps 35061 PostScript
Tune-37649-_Thompsons_V4_1773-1780_PD.txt 455 Plain-text file with the extracted tune(s)
Tune-37649-get.log 46081 Log file, useful mostly for debugging
These files should be available for 24 hours.