Please answer a question about the following article about Madonna (entertainer):

From the beginning of 2014, Madonna began to make multiple media appearances. She appeared at the 56th Annual Grammy Awards in January 2014, performing "Open Your Heart" alongside rappers Macklemore & Ryan Lewis and singer Mary Lambert, who sang their single "Same Love", as 33 couples were wed onstage, officiated by Queen Latifah. 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). She also extended her business ventures and in February 2014 the singer premiered MDNA Skin, a range of skin care products, in Tokyo, Japan. After visiting her hometown of Detroit during May 2014, Madonna decided to contribute funds to three of the city's organizations, to help eliminate poverty from there. The singer released a statement saying that she was inspired by their work, adding that "it was obvious to me that I had to get involved and be part of the solution to help Detroit recover".

What award ceremony did Madonna appeared in?
56th Annual Grammy Awards