How can we sing?

Psalm 137:1-4 1 By the rivers of Babylon we sat and wept when we remembered Zion.2 There on the poplars we hung our harps, 3 for there our captors asked us for songs, our tormentors demanded songs of joy; they said, “Sing us one of the songs of Zion!”4 How can we sing the songs of the Lord while in a foreign land?Our Psalm today, penned after the nation of Israel had be...