I have just discovered that those with aphasia can actually sing even though they can't speak.
Apparently singing and melody are processed in a different part of the brain from speech.
Was anyone else aware of that?

Cassie*, yes. This is mentioned often with FTD. Singing is farther back in the brain. People who never sang before sometimes develop perfect pitch (though I don't know how often). With FTD as the front part of the brain deteriorates portions farther back try to pick up the work, which results in, temporarily, enhanced abilities associated with that part of the brain.

I remember reading that Joni Mitchell had a childhood stuttering problem so she was taught to sing what she wanted to say, which eventually resulted in her career.

Paulc and Cassie: I didn't know that singing occurred farther back in the brain. That would explain why my husband sings so much. He has FTD with an Alzheimer overlap. He didn't sing so much before dementia but now he sings every day, all kinds of songs, mostly songs from his youth and when we were first married; he even sings in Polish, the language he spoke to his parents. This explains a lot. No one complains about him singing; everyone seems to enjoy it. Sometimes, though, he accompanies himself by pounding on the table with his fist.

He is doing so well at the nursing home now. He still asks who will bring him home though and for the first time in many months, today he introduced me to the aide as his wife! I could not believe it. If I didn't know better, sometimes I feel he could come home, but I know he can't. In September he will have been there for two years!