Who is Umm Kulthum from Miramar and what is their importance?

Umm Kulthum is an actual historical figure, who is often mentioned in the novel. She was an Egyptian singer, and she had the most famous voice in the Middle East at the time of this novel. Umm broadcasts the first Thursday of every month, which no one wants to miss, and everyone at the Miramar Pension gather around the radio, eating and drinking lavishly in anticipation of the event. By the late 1960s, Umm's voice is beginning to fade, but the elderly Amer Wagdi declares that her voice is "the only thing today for which the past can provide no equal".