A Rhyme of Lore

Gandalf sang this to himself while he rode with Peregrin Took to Minas Tirith after Pippin looks in the palantír. Pippin didn't hear all of it, just the lines below. A Rhyme of Lore was about the Númenoreans, led by Elendil, who escaped the sinking of the island of Númenor; it was preserved by the Dúnedain.
 * Tall ships and tall kings
 * Three times three,
 * What brought they from the foundered land
 * Over the flowing sea?
 * Seven stars and seven stones
 * And one white tree.