Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/1804/BostonCollection.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-7292-BostonCollection.ps) >>/Users/jc/w/tmp/Tune-7292-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/1804/BostonCollection.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-7292-1769_Bremner_SRCD.abc 154 ABC music file with the extracted tune(s)
Tune-7292-1769_Bremner_SRCD.ps 6 PostScript
Tune-7292-1769_Bremner_SRCD.txt 154 Plain-text file with the extracted tune(s)
Tune-7292-BostonCollection.abc 153 ABC music file with the extracted tune(s)
Tune-7292-BostonCollection.ps 6 PostScript
Tune-7292-BostonCollection.txt 153 Plain-text file with the extracted tune(s)
Tune-7292-get.log 8434 Log file, useful mostly for debugging
Tune-72920-get.log 5137 Log file, useful mostly for debugging
Tune-72922-get.log 4131 Log file, useful mostly for debugging
These files should be available for 24 hours.