pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-33552-Bonnie_Lass_o_Bon_Accord_1-A-32-3.ps) >>/Users/jc/w/tmp/Tune-33552-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/abc/session/air/Bonnie_Lass_o_Bon_Accord_1-A-32-3.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-33552-Bonnie_Lass_o_Bon_Accord_1-A-32-3.abc 543 ABC music file with the extracted tune(s)
Tune-33552-Bonnie_Lass_o_Bon_Accord_1-A-32-3.ps 36798 PostScript
Tune-33552-Bonnie_Lass_o_Bon_Accord_1-A-32-3.txt 543 Plain-text file with the extracted tune(s)
Tune-33552-get.log 4867 Log file, useful mostly for debugging
These files should be available for 24 hours.