A tall tree in the .... what?

A tree was there! O pure and higher growing!
O Orpheus sings! O tall tree in the ear!
And all fell still. Yet even in the unknowing
a new start grew, signal, an atmosphere.

Thus begins the Austrian poet Rainer Marie Rilke's famous poem cycle: The Sonnets to Orpheus. (This translation from the original German was done by me and my late friend the world-class Welsh poet Leslie Norris.)