A scandal that is a sad commentary on national politics.
When a political pundit is discussing the president's vote on a new bill, this is an example of political commentary.
When a golf announcer narrates a major golf tournament, describing each player's shots and talking about his score, this is an example of commentary.
When there is a DVD-director's cut of a movie that is accompanied by the director explaining his choices, this explanation is an example of commentary.
Two retired players did the commentary for the game.
A commentary on Plato's Republic ; biblical commentaries.
Caesar's commentaries on the war in Gaul.