Rhino’s Joni Mitchell Archives series has been dependably running since 2020, offering alternating box sets featuring troves of unreleased material from the folk legend and remastered versions of the album eras they cover. With the most recent box collecting her last four albums for the Asylum label – Hejira (1976), Don Juan’s Reckless Daughter (1977), Mingus (1979) and the live Shadows and Light (1980) – today’s new announcement closes that same chapter, offering hours of unreleased live and studio material tied to those records. Joni Mitchell Archives Vol. 4: The Asylum Years (1976-1980), released October 4, will feature six CDs…