pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4766-30671_Humphreys_Gavott.ps) >>/Users/jc/w/tmp/Tune-4766-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/EliasHowe/MusiciansCompanionP3/30671_Humphreys_Gavott.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Coll_4766.log 441610 Log file, useful mostly for debugging
Coll_47660.log 448608 Log file, useful mostly for debugging
Coll_47668.log 469611 Log file, useful mostly for debugging
Form_47662.log 1012 Log file, useful mostly for debugging
Form_47664.log 965 Log file, useful mostly for debugging
Tune-4766-30671_Humphreys_Gavott.abc 906 ABC music file with the extracted tune(s)
Tune-4766-30671_Humphreys_Gavott.ps 36652 PostScript
Tune-4766-30671_Humphreys_Gavott.txt 906 Plain-text file with the extracted tune(s)
Tune-4766-get.log 6373 Log file, useful mostly for debugging
Tune-47660-get.log 1351 Log file, useful mostly for debugging
These files should be available for 24 hours.