I want to know the answer to the following question:
Which singer did she join on MTV Unplugged to sing?
All the background I'm provided with is that "Days later, she joined singer Miley Cyrus on her MTV Unplugged special, singing a mash-up of "Don't Tell Me" and Cyrus' single "We Can't Stop" (2013).". Is that enough to answer the question?
Answer: yes