How about songs that have something that's a part of our planet in the title. For instance, mountains, hills, valleys, caverns, canyons, grass, trees, flowers, rocks, bodies of water. Anything that's a part of Earth (except animals, cause we've already done those) "Rose of Tralee", The pale moon was rising above the green mountain, the sun was declining beneath the blue sea, when I strayed with my love to the pure crystal fountain, that stands in the beautiful vale of Tralee. (An Irish ballad.) "Climb Every Mountain", from the 1959 musical 'Sound of Music' by Rogers and Hammerstein. "Somewhere Beyond the Sea", recorded by Bobby Darrin/Frank Sinatra and others.