Katharine McPhee and her sister Adriana surprised their mom Peisha for a special birthday celebration during Michael Orland’s Open Mic Night at The Write-Off Room in Studio City on Monday, November 6.

Katharine and Adriana performed a medley of “Sisters”, “If Momma Was Married” and “Mama, a Rainbow”. Later on, Katharine surprised the audience with a medley of “I’ll Be Seeing You” and “Some Other Time”.

Watch the complete performance above, or check the post down here to see some funny highlights of Katharine and Adriana’s performance: