Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1805/CJSurtees.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-6450-CJSurtees.ps) >>/Users/jc/w/tmp/Tune-6450-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1805/CJSurtees.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-6450-CJSurtees.abc 146 ABC music file with the extracted tune(s)
Tune-6450-CJSurtees.ps 6 PostScript
Tune-6450-CJSurtees.txt 146 Plain-text file with the extracted tune(s)
Tune-6450-get.log 4041 Log file, useful mostly for debugging
Tune-64504-2412_Negro_Sand_Dance-001.svg 26406 Scalable Vector Graphics format
Tune-64504-2412_Negro_Sand_Dance.abc 579 ABC music file with the extracted tune(s)
Tune-64504-2412_Negro_Sand_Dance.txt 579 Plain-text file with the extracted tune(s)
Tune-64504-get.log 4640 Log file, useful mostly for debugging
Tune-64506-24CountryDances_1799_Preston.abc 165 ABC music file with the extracted tune(s)
Tune-64506-24CountryDances_1799_Preston.ps 6 PostScript
Tune-64506-24CountryDances_1799_Preston.txt 165 Plain-text file with the extracted tune(s)
Tune-64506-get.log 4371 Log file, useful mostly for debugging
These files should be available for 24 hours.