Got HTTP status 404 Not Found for "http://john-chambers.us/~jc/music/book/Kerr_MM/cresc.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-8172-cresc.ps) >>/Users/jc/w/tmp/Tune-8172-get.log 2>&1" returned status 256
http://john-chambers.us/~jc/music/book/Kerr_MM/cresc.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_81721.log 564445 Log file, useful mostly for debugging
Coll_81723.log 560230 Log file, useful mostly for debugging
Coll_81726.log 294166 Log file, useful mostly for debugging
Tune-8172-cresc.abc 145 ABC music file with the extracted tune(s)
Tune-8172-cresc.ps 6 PostScript
Tune-8172-cresc.txt 145 Plain-text file with the extracted tune(s)
Tune-8172-get.log 5382 Log file, useful mostly for debugging
Tune-81725-get.log 5569 Log file, useful mostly for debugging
Tune-81727-24CountryDances_1808_Goulding_AK.abc 177 ABC music file with the extracted tune(s)
Tune-81727-24CountryDances_1808_Goulding_AK.ps 6 PostScript
Tune-81727-24CountryDances_1808_Goulding_AK.txt 177 Plain-text file with the extracted tune(s)
Tune-81727-get.log 4501 Log file, useful mostly for debugging
These files should be available for 24 hours.