April Rain Song
by Langston Hughes
Let the rain kiss you.
Let the rain beat upon your head with silver liquid drops.
Let the rain sing you a lullaby.
The rain makes still pools on the sidewalk.
The rain makes running pools in the gutter.
The rain plays a little sleep-song on our roof at night－
And I love the rain.
Which word in the poem is closest in meaning to sleep-song?