Ruth Bader Ginsburg
Ruth Bader GinsburgReuters

Supreme Court Justice Ruth Bader Ginsburg appeared in public for the first time since cancer surgery in December, to attend a concert honoring her law career.

Ginsburg, 85, on Monday attended “Notorious RBG in Song” performed at the National Museum of Women in the Arts in Washington, the Washington Post reported. The program was created and performed by Ginsburg’s daughter-in-law, soprano Patrice Michaels, and presented to high school students by the National Constitution Center.

According to the Post, Ginsburg sat in the back and many in the audience did not know she was there.

Following the surgery in December to remove cancer from her lungs, Ginsburg was declared cancer-free. She has had two other bouts of cancer.

In January she missed oral arguments for the first time in her 25-year tenure on the court. She will vote in the cases based on briefs and transcripts, the Post reported, and has participated from home in deciding which cases the court has accepted or rejected for its docket.

Her son, James, told the Post that Ginsburg walks a mile a day and is working with her trainer again.

It is not known if she will attend the State of the Union address on Tuesday, which is not mandatory. She missed last year’s address due to a scheduling conflict.

The Supreme Court will meet next in public session on Feb. 19.