Abby, if he's a "new slain knight," Lady may have been with him when it happened. Sounds like he was home on furlough, enjoying a bit of hunting when his bow misfired or something.

Then again, in one version, Lady has ta'en another mate. Maybe the mate offed her former husband. She may not have done the deed, but she's an accessory. Classic folk murder - take someone hunting in order to do away with them.

I could very easily and quickly do a MIDI of the tune I know from the singing of Maddy Prior. It's different from the ones in the DB, but I have no idea if it's the one Malcolm refers to.