Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/CR/RSCDS_Graded2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-4087-RSCDS_Graded2.ps) >>/Users/jc/w/tmp/Tune-4087-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/CR/RSCDS_Graded2.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_4087.log 459809 Log file, useful mostly for debugging
Coll_40871.log 479409 Log file, useful mostly for debugging
Coll_40878.log 466809 Log file, useful mostly for debugging
Coll_40879.log 472409 Log file, useful mostly for debugging
Tune-4087-RSCDS_Graded2.abc 148 ABC music file with the extracted tune(s)
Tune-4087-RSCDS_Graded2.ps 6 PostScript
Tune-4087-RSCDS_Graded2.txt 148 Plain-text file with the extracted tune(s)
Tune-4087-get.log 4117 Log file, useful mostly for debugging
Tune-40870-get.log 1361 Log file, useful mostly for debugging
Tune-40872-get.log 4476 Log file, useful mostly for debugging
These files should be available for 24 hours.