Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/JamesOswald/CPC/21171_Seaforths_Farewell.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-5712-all.ps) >>/Users/jc/w/tmp/Tune-5712-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/JamesOswald/CPC/21171_Seaforths_Farewell.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
Tune-5712-NewNewNothing_PLFD1651_069.abc 319 ABC music file with the extracted tune(s)
Tune-5712-NewNewNothing_PLFD1651_069.ps 32266 PostScript
Tune-5712-NewNewNothing_PLFD1651_069.txt 319 Plain-text file with the extracted tune(s)
Tune-5712-all.abc 176 ABC music file with the extracted tune(s)
Tune-5712-all.ps 6 PostScript
Tune-5712-all.txt 176 Plain-text file with the extracted tune(s)
Tune-5712-get.log 8974 Log file, useful mostly for debugging
Tune-57123-GloryoftheWestThe_PLFD1651_028-001.svg 14332 Scalable Vector Graphics format
Tune-57123-GloryoftheWestThe_PLFD1651_028.abc 441 ABC music file with the extracted tune(s)
Tune-57123-GloryoftheWestThe_PLFD1651_028.txt 441 Plain-text file with the extracted tune(s)
Tune-57123-get.log 4626 Log file, useful mostly for debugging
These files should be available for 24 hours.