Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/JamesOswald/CPC/14031_Roselana_Castle.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7823-all.ps) >>/Users/jc/w/tmp/Tune-7823-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/JamesOswald/CPC/14031_Roselana_Castle.abc/all

Error exit status 256; here are some files to check:
[get.cgi V=1/1 B=0 scale=0.55 512x512 PNG]
filesizedescription
Coll_78239.log 149899 Log file, useful mostly for debugging
Tune-7823-all.abc 173 ABC music file with the extracted tune(s)
Tune-7823-all.ps 6 PostScript
Tune-7823-all.txt 173 Plain-text file with the extracted tune(s)
Tune-7823-get.log 4069 Log file, useful mostly for debugging
Tune-78230-20992_He_Loves_and_He_Rides_Away.abc 731 ABC music file with the extracted tune(s)
Tune-78230-20992_He_Loves_and_He_Rides_Away.txt 731 Plain-text file with the extracted tune(s)
Tune-78230-get.log 3524 Log file, useful mostly for debugging
These files should be available for 24 hours.