Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1818/Glen2.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-2056-Glen2.ps) >>/Users/jc/w/tmp/Tune-2056-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1818/Glen2.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_20567.log 1336593 Log file, useful mostly for debugging
Sess-20561.log 118 Log file, useful mostly for debugging
Sess-20566.log 119 Log file, useful mostly for debugging
Tune-2056-Glen2.abc 142 ABC music file with the extracted tune(s)
Tune-2056-Glen2.ps 6 PostScript
Tune-2056-Glen2.txt 142 Plain-text file with the extracted tune(s)
Tune-2056-JamesJohnson_ScotsMusicalMuseumV4-V1.abc 173 ABC music file with the extracted tune(s)
Tune-2056-JamesJohnson_ScotsMusicalMuseumV4-V1.txt 173 Plain-text file with the extracted tune(s)
Tune-2056-get.log 10899 Log file, useful mostly for debugging
Tune-20566-062_French_Grenadiers_march.abc 677 ABC music file with the extracted tune(s)
Tune-20566-062_French_Grenadiers_march.ps 33412 PostScript
Tune-20566-062_French_Grenadiers_march.txt 677 Plain-text file with the extracted tune(s)
Tune-20566-get.log 5006 Log file, useful mostly for debugging
These files should be available for 24 hours.