Got HTTP status 404 Not Found for "http://roaringjelly.org/~jc/music/book/1784/Kerr_MM4-V1.abc"
pngcmd="(./ps2png 512 512 /Users/jc/w/tmp/Tune-9988-Kerr_MM4-V1.ps) >>/Users/jc/w/tmp/Tune-9988-get.log 2>&1" returned status 256
http://roaringjelly.org/~jc/music/book/1784/Kerr_MM4-V1.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-9988-Kerr_MM4-V1.abc 148 ABC music file with the extracted tune(s)
Tune-9988-Kerr_MM4-V1.ps 6 PostScript
Tune-9988-Kerr_MM4-V1.txt 148 Plain-text file with the extracted tune(s)
Tune-9988-get.log 4087 Log file, useful mostly for debugging
Tune-99882-10502_Bosses_Hornpipe.abc 671 ABC music file with the extracted tune(s)
Tune-99882-10502_Bosses_Hornpipe.ps 34783 PostScript
Tune-99882-10502_Bosses_Hornpipe.txt 671 Plain-text file with the extracted tune(s)
Tune-99882-get.log 4953 Log file, useful mostly for debugging
These files should be available for 24 hours.