Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/JamesOswald/CPC/21512_the_Sun_beam.abc/all"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6612-all.ps) >>/Users/jc/w/tmp/Tune-6612-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/JamesOswald/CPC/21512_the_Sun_beam.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_66124.log 149255 Log file, useful mostly for debugging
Tune-6612-30763_Fraziers_Reel.abc 643 ABC music file with the extracted tune(s)
Tune-6612-30763_Fraziers_Reel.ps 35672 PostScript
Tune-6612-30763_Fraziers_Reel.txt 643 Plain-text file with the extracted tune(s)
Tune-6612-all.abc 170 ABC music file with the extracted tune(s)
Tune-6612-all.ps 6 PostScript
Tune-6612-all.txt 170 Plain-text file with the extracted tune(s)
Tune-6612-get.log 8880 Log file, useful mostly for debugging
Tune-66126-111_Cromlets_Lilt.abc 1258 ABC music file with the extracted tune(s)
Tune-66126-111_Cromlets_Lilt.gif 0 Graphics Interchange Format, the proprietary scan-line picture format
Tune-66126-111_Cromlets_Lilt.ps 39332 PostScript
Tune-66126-111_Cromlets_Lilt.txt 1258 Plain-text file with the extracted tune(s)
Tune-66126-get.log 5362 Log file, useful mostly for debugging
These files should be available for 24 hours.