pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-78656-20072_Canaan.ps) >>/Users/jc/w/tmp/Tune-78656-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/EliasHowe/MusiciansCompanionP2/20072_Canaan.abc

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Tune-78656-20072_Canaan.abc 721 ABC music file with the extracted tune(s)
Tune-78656-20072_Canaan.ps 34005 PostScript
Tune-78656-20072_Canaan.txt 721 Plain-text file with the extracted tune(s)
Tune-78656-get.log 17221 Log file, useful mostly for debugging
These files should be available for 24 hours.