I wanted to mention this limited release blu-ray here because it hasn't been mentioned in any of the blu-ray forums that I've seen. It is available either as a deluxe set with softbound book, blu-ray, DVD (with bonus concert footage and interviews) and a two CD set with music that wasn't filmed; or you can order just the blu-ray and DVD. I got the deluxe set and I haven't listened to the CDs or DVD yet, but I watched the blu-ray and it was fantastic.
If you aren't familiar with this film, it is the Jazz on a Summer's Day or Woodstock or Monterey Pop of bluegrass music. Incredible line up of performers- Ralph Stanley, Osborne Brothers, Roy Acuff, Mac Wiseman, J.D. Crowe, Jimmy Martin, Del McCoury, Earl Scruggs, Chubby Wise, Ricky Skaggs... all amazing musicians. It was shot on 16mm with complete cooperation of the musicians and event organizers so the photography and sound are excellent.
Like Jazz on a Summer's Day, it has footage of the audience and environment as well as the musical acts, so it gives great insight into the old time country scene back in that time. People would drive in from all over the country to Camp Springs Bluegrass Park in North Carolina, and they'd pitch tents and camp in the field. Some of the most fun footage is after the show, where performers go out to the campground and play with musicians in the crowd by a campfire. Other highlights are when they gather together every banjo player or fiddle player on the stage to perform together and take turns soloing. The stage is packed with a who's who of musicians.
The blu-ray was restored from the original surviving film elements in 4K and a very tasteful 5.1 surround track was created. I guess this was done back in 2019, but I never heard about it. I think the only place you can get it is directly from the company, or on PBS pledge breaks.
Here is an unrestored intro to the film. It doesn't represent the quality of the blu-ray, which is in 1.85 and HD.
Here is a clip of the Osbornes that represents the sound and image quality of the blu-ray better.
I highly recommend this. I think it's one of the most important concert films ever made and they did a great job of restoring it and packaging it with great supplements and a beautiful book. Check it out...
https://bluegrasscountrysoul.com