midicmd="abc2midi /Users/jc/w/tmp/Tune-26997-tunebook.abc -v -o /Users/jc/w/tmp/Tune-26997-tunebook.midi >>/Users/jc/w/tmp/Tune-26997-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
Coll_26997.log 136152 Log file, useful mostly for debugging
Tune-26997-get.log 0 Log file, useful mostly for debugging
Tune-26997-tunebook.abc 507 ABC music file with the extracted tune(s)
Tune-26997-tunebook.malt 1527 Musical Instrument Digital Interface, alternate name for midi format
Tune-26997-tunebook.mid 1527 Musical Instrument Digital interface, shortened name for midi format
Tune-26997-tunebook.midi 1527 Musical Instrument Digital Interface, electronic version of the tune(s)
Tune-26997-tunebook.txt 507 Plain-text file with the extracted tune(s)
These files should be available for 24 hours.