Guarda Streamingcommunity. Narrated by cinema legend Franco Zeffirelli, this intimate made-for-television documentary traces the life and times of the mercurial Maria Callas, one of the most renowned and respected operatic divas of the mid-20th century. Rare authentic footage, candid interviews and breathtaking performances help paint a portrait of an artist remembered as much for her quick and explosive temper as she is for her immeasurable talent.