Yesterday, we honored Joni Mitchell with a song from Trousdale. Today, we turn to the queen herself. Her seminal album “Blue” turned 50 this year. To celebrate, a new compilation, “Blue 50 (Demos & Outtakes),” has been issued  offering a different perspective on one of the greatest albums of all time, plus an unreleased song that she liked to perform but was cut from the original album. Here is “Hunter.”