Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Book18/OriginallyMine.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7894-OriginallyMine.ps) >>/Users/jc/w/tmp/Tune-7894-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Book18/OriginallyMine.abc

Error exit status 256; here are some files to check:
[P=tuneget V=1/1 B=0 scale=0.70 512x512 PNG]
filesizedescription
Tune-7894-OriginallyMine.abc 153 ABC music file with the extracted tune(s)
Tune-7894-OriginallyMine.ps 6 PostScript
Tune-7894-OriginallyMine.txt 153 Plain-text file with the extracted tune(s)
Tune-7894-get.log 12104 Log file, useful mostly for debugging
Tune-78940-get.log 4369 Log file, useful mostly for debugging
Tune-78942-JamesOswald_CPC-abc1.abc 170 ABC music file with the extracted tune(s)
Tune-78942-JamesOswald_CPC-abc1.ps 6 PostScript
Tune-78942-JamesOswald_CPC-abc1.txt 170 Plain-text file with the extracted tune(s)
Tune-78942-get.log 4402 Log file, useful mostly for debugging
Tune-78944-Button_Whitaker_12ElegantNewDances_1810.abc 178 ABC music file with the extracted tune(s)
Tune-78944-Button_Whitaker_12ElegantNewDances_1810.txt 178 Plain-text file with the extracted tune(s)
Tune-78944-get.log 13484 Log file, useful mostly for debugging
Tune-78945-get.log 3542 Log file, useful mostly for debugging
Tune-78948-get.log 4043 Log file, useful mostly for debugging
These files should be available for 24 hours.