Donna Summer

 — the Queen of Disco — died this morning after a battle with cancer … has learned.

We're told Summer was in Florida at the time of her death. She was 63 years old.

Sources close to Summer tell … the singer was trying to keep the extent of her illness under wraps. We spoke to someone who was with Summer a couple of weeks ago … who says she didn't seem too bad.

In fact, we're told she was focused on trying to finish up an album she had been working on.

Summer was a 5-time Grammy winner who shot to superstardom in the '70s with hits like “Last Dance,” “Hot Stuff” and “Bad Girls.”

[iframe width=”550″ height=”403″ src=”http://www.youtube.com/embed/f0h8Pjf4vNM?rel=0″ frameborder=”0″ allowfullscreen] Music video by Donna Summer performing I Feel Love. (C) 1978 The Island Def Jam Music Group
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