Supreme Court Justice Ruth Bader Ginsburg is making her first public appearance since undergoing lung cancer surgery in December.

The 85-year-old Ginsburg is attending a concert at a museum a few blocks from the White House that is being given by her daughter-in-law and other musicians. Patrice Michaels is married to Ginsburg’s son, James. Michaels is a soprano and composer.

The concert is dedicated to Ginsburg’s life in the law.

Ginsburg had surgery in New York on Dec. 21. She missed arguments at the court in January, her first illness-related absence in more than 25 years as a justice.

She has been recuperating at her home in Washington since late December.

Ginsburg had two previous bouts with cancer. She had colorectal cancer in 1999 and pancreatic cancer in 2009.

The justice sat in the back of the darkened auditorium at the National Museum of Women in the Arts.

The National Constitution Center, which sponsored the concert, did not permit photography.

James Ginsburg said before the concert that his mother is walking a mile a day and meeting with her personal trainer twice a week.

The performance concluded with a song set to Ginsburg’s answers to questions.

In introducing the last song, Michaels said, “bring our show to a close, but not the epic and notorious story of RBG.”