Before my slow-drip deep-dive into the career of the late Christine McVie sinks into her most famous and overly analyzed phase, starting with Fleetwood Mac’s transformative breakthrough of ‘75, I think it’s worth taking a two-years-prior detour into this barely buried treasure. Frankly, Buckingham Nicks, a highly accomplished debut that bafflingly bombed and got the duo booted from Polydor, looms almost as large in the Mac legacy as touchstones that came before or after it.