Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/kendy/RSCDS_Graded1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-3974-RSCDS_Graded1.ps) >>/Users/jc/w/tmp/Tune-3974-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/kendy/RSCDS_Graded1.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_39744.log 557420 Log file, useful mostly for debugging
Coll_39746.log 292760 Log file, useful mostly for debugging
Coll_39749.log 1074020 Log file, useful mostly for debugging
Tune-3974-RSCDS_Graded1.abc 151 ABC music file with the extracted tune(s)
Tune-3974-RSCDS_Graded1.ps 6 PostScript
Tune-3974-RSCDS_Graded1.txt 151 Plain-text file with the extracted tune(s)
Tune-3974-get.log 15521 Log file, useful mostly for debugging
Tune-39747-get.log 5265 Log file, useful mostly for debugging
Tune-39749-get.log 4307 Log file, useful mostly for debugging
These files should be available for 24 hours.