Neil Young has more unfinished or unreleased projects than Brian Wilson and Orson Welles combined, so it is good to see him follow through on his long-promised archival series. His most recent archival release, Live At Massey Hall 1971, is a good one. I recommend splurging on the CD/DVD version if for no other reason than to hear the better sound quality of which DVD is capable (CDs sample music at 44.1 kHz/16-bits, while DVDs can sample at 96kHz/24-bits). Young himself has long complained about the sub-par quality of CD sound.
The Massey Hall concert material was originally considered for release between After The Gold Rush and Harvest, but Young was keen to release Harvest first. It would have been unusual to release a live LP that previewed music from an upcoming studio release, but why the album wasn't released in the wake of Harvest's enormous success is a mystery. My best guess is that Young was eager to alienate the middle-of-the-road audience "Heart Of Gold" brought him, and releasing this album then would have been at cross purposes with that aim. (The cause of alienating his audience was much better served by Time Fades Away, the live album he did release after Harvest.)
The sound of the DVD is amazingly good. Turn off your TV, close your eyes and you will feel like you have been transported to Massey Hall circa 1971 to listen to Neil Young at the peak of his creative powers. I listened to this last night, and by the time I was done I almost felt like I had gotten a contact high from the second-hand marijuana smoke at Massey Hall--that's how realistic this sounds.
Amazon has a video for "The Needle And The Damage Done," and "Old Man" and "Ohio" are available on YouTube.