midicmd="abc2midi /Users/jc/w/tmp/Tune-99789-112_Caledonia_Reel-G-16-2.abc -v -o /Users/jc/w/tmp/Tune-99789-112_Caledonia_Reel-G-16-2.midi >>/Users/jc/w/tmp/Tune-99789-get.log 2>&1" returned status 256.

Error exit status 256; here are some files to check:
[P=get.cgi V=1/1 B=0 scale=0.60 512x512 ]
filesizedescription
Tune-99789-112_Caledonia_Reel-G-16-2.abc 911 ABC music file with the extracted tune(s)
Tune-99789-112_Caledonia_Reel-G-16-2.malt 0 Musical Instrument Digital Interface, alternate name for midi format
Tune-99789-112_Caledonia_Reel-G-16-2.mid 0 Musical Instrument Digital interface, shortened name for midi format
Tune-99789-112_Caledonia_Reel-G-16-2.midi 0 Musical Instrument Digital Interface, electronic version of the tune(s)
Tune-99789-112_Caledonia_Reel-G-16-2.txt 911 Plain-text file with the extracted tune(s)
Tune-99789-get.log 4013 Log file, useful mostly for debugging
These files should be available for 24 hours.