Music moves, music soothes and most important, music can improve your mood. Press play on these happy songs for a boost of cheer. The power of music is no joke—it can affect our mind, body and mood.

Though released ahead of Christmas 1971, "Happy Xmas (War Is Over)" and its origins go back several years earlier. The song's context is the Vietnam War era and the 1960s counterculture, when Lennon ...