Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Children/BB50.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-1396-BB50.ps) >>/Users/jc/w/tmp/Tune-1396-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Children/BB50.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_1396.log 579900 Log file, useful mostly for debugging
Coll_13967.log 287140 Log file, useful mostly for debugging
Coll_13968.log 283672 Log file, useful mostly for debugging
Tune-1396-BB50.abc 145 ABC music file with the extracted tune(s)
Tune-1396-BB50.ps 6 PostScript
Tune-1396-BB50.txt 145 Plain-text file with the extracted tune(s)
Tune-1396-get.log 9103 Log file, useful mostly for debugging
Tune-13964-get.log 4461 Log file, useful mostly for debugging
Tune-13967-BostonCollection.abc 158 ABC music file with the extracted tune(s)
Tune-13967-BostonCollection.pdf 2217 Portable Data Format
Tune-13967-BostonCollection.ps 6 PostScript
Tune-13967-BostonCollection.txt 158 Plain-text file with the extracted tune(s)
Tune-13967-get.log 5088 Log file, useful mostly for debugging
Tune-13969-get.log 1528 Log file, useful mostly for debugging
These files should be available for 24 hours.