There's no way for sure to know what he would have been listening to at 77 years of age. However, he would not have been your typical old man. Elvis was already scared to death at 39 afraid of turning 40 and growing old and having grey hair. Elvis was always into the new music scene and commented on it during the comeback special. He performed modern day songs by other artists at his concerts routinely.
As for would he have liked rap.
There's no way anyone (including Priscilla) can say he wouldn't. Although it's possible that he would have liked it years ago when it was likable back in the 80's and 90's. Just because you and I do not care for it doesn't mean that he wouldn't have either. Klein, Schilling, West, and others have all commented in the past that Elvis would have liked some rap artists. Rap is today what the blues were back in Elvis' youth. I'm sure he would have given it a chance and viewed it with an open mind.
He probably would have even invited the local Memphis rappers like Three-Six Mafia and Yo Gotti to Graceland. Unfortunately, we'll never know.
