pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-56923-21173_Barcarole_Sett_tune_6.ps) >>/Users/jc/w/tmp/Tune-56923-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/EliasHowe/MusiciansCompanionP2/21173_Barcarole_Sett_tune_6.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Tune-56923-21173_Barcarole_Sett_tune_6.abc 1037 ABC music file with the extracted tune(s)
Tune-56923-21173_Barcarole_Sett_tune_6.ps 37996 PostScript
Tune-56923-21173_Barcarole_Sett_tune_6.txt 1037 Plain-text file with the extracted tune(s)
Tune-56923-IgnatiusSancho_CNS_v1.abc 158 ABC music file with the extracted tune(s)
Tune-56923-IgnatiusSancho_CNS_v1.ps 6 PostScript
Tune-56923-IgnatiusSancho_CNS_v1.txt 158 Plain-text file with the extracted tune(s)
Tune-56923-get.log 9521 Log file, useful mostly for debugging
These files should be available for 24 hours.