Click on the 'Listen' button above to hear this interview.

Prince transformed how we understood music — this complex and iconic artist who transcended genre, gender, race, fashion, and culture died on Thursday at the age of 57. It's hard to find any artist or music fan who wasn't influenced by him. Even President Obama addressed Prince's death yesterday.

"As one of the most gifted and prolific musicians of our time, Prince did it all," the president said in a statement. "Nobody's spirit was stronger, bolder, or more creative."

Many Takeaway listeners also had strong reactions to the sudden news of Prince's death yesterday. 

"Prince always acted with the utmost integrity," wrote a listener in Columbus, Ohio. "He was a tremendous talent and class act. I find his sudden death absolutely tragic and leaving a large hole in our culture and society."

R&B singer The Weeknd simply couldn't believe it when he heard the news.

"I just woke up but it feels like I'm dreaming. We live in a world where Prince passes away?" the singer tweeted. 

It did seem like Prince was otherworldly at times, either channeling his music and signature look from outside, or perhaps just born to a different beat than the mere earthlings around him. 

BBC reporter and Prince superfan Mobeen Azhar went looking for the answer to the enigma of Prince last year. He traveled to Prince's hometown in Minnesota to search for the existence of his vault, which apparently holds at least 2,000 unreleased tracks.

"I spoke to people from every era of Prince's career and people that he worked with, and they would tell me that not only is there unreleased studio recordings, there's also material from concerts, there's live recordings, [and] there's video footage," says Azhar, director of the 2015 documentary "Hunting for Prince's Vault." 

According to Azhar, Prince's vault also includes a number of fully produced promotional videos for singles that have never been released, and at least two feature length films that have never been seen by the public.

"The question isn't really, 'Does the vault exist?'" says Azhar. "The question is how much material is in there."

Azhar believes that there is so much unreleased material in the vault that a new Prince album could drop every year for the next 100 years. But Prince's bandmate Sonny T. says that having so much music is a tricky blessing.

"He said that if Prince released everything from the vault, there's so much music that no one could live long enough to hear all of these thousands of hours of music," says Azhar.

But will any of this music ever see the light of day? Click on the 'Listen' button above to hear our full interview with Azhar, and check out a clip from his documentary below.