LETTERMAN The Last Giant of Late Night

David Letterman spent 33 years hosting innovative late-night TV for America’s delectation before turning over “Late Show” to Stephen Colbert in 2015.  “Letterman: The Last Giant of Late Night,” a book that does impressive triple duty as an acute portrait of stardom, an insightful chronicle of three rambunctious decades of pop-culture evolution, and a very brainy fan’s notes. Suggestive as it is of rage, not just a chronic case of the Eeyore blues, the striking word “seething” is a useful window into Letterman’s uniqueness.