I really like that it has the lines: "Come, my friends, 'Tis not too late to seek a newer world. Push off, and sitting well in order smite the sounding furrows; for my purpose holds to sail beyond the sunset, and the baths of all the western stars, until I die" in it as they are perhaps my favourite lines in the history of poetry. Gielgud's voice was perfect for a performance of the poem.
Terry herself perfomed Tennyson on stage in a number of his plays (Not as well known as his poetry but he did write a number of them). Most notability in the 1893 production of Becket (Photos of her in the role of Rosamund can be found here and here)