Mandolinist Mike Compton has released an album (Rare and Fine) of unreleased and many unrecorded  Bill Monroe pieces.

Here's the video of Orange Blossom Breakdown.

Mike Compton on Mandolin, Russ Carson on banjo, Jeremy Stephens on guitar, and Mike Bub on bass, Rare and Fine also features Shad Cobb, Laura Orshaw, and Michael Cleveland on fiddle.