Madonna to join Pussy Riot at human rights concert

Madonna's not done with her recent string of public appearances -- she also has signed on to introduce members of Pussy Riot at Amnesty International's human rights concert in New York.

The 55-year-old pop star made the announcement Wednesday morning on social media. She's been busy of late, appearing on Sunday's Grammy Awards with Macklemore & Ryan Lewis and singing with Miley Cyrus during an "MTV Unplugged" taping Tuesday.

Madonna said in a statement that she admires Maria Alyokhina and Nadezhda Tolokonnikova. They were recently released after nearly two years in jail following a conviction for hooliganism when they staged a protest in a Russian church.

The Feb. 5 Bringing Human Rights Home concert at the Barclays Center in Brooklyn also includes Imagine Dragons, Lauryn Hill, The Flaming Lips and others.