Jennifer Garner Plays the Saxophone to Celebrate Reese Witherspoon's Birthday - Watch!

Jennifer Garner found a special way to pay musical tribute to Reese Witherspoon on her birthday!

The 46-year-old Peppermint actress uploaded a video on her Instagram in celebration of the Big Little Lies actress, who turned 43 on Friday (March 22).

PHOTOS: Check out the latest pics of Jennifer Garner

“Many moons ago, my high school marching band played this song for homecoming. Today I play it for my boo, @reesewitherspoon. ♥️We have a groovy kind of love.♥️ Happy birthday, Lady. #bandgeeksarethebestgeeks 🎷 #havethebestday,” Jennifer captioned the adorable post.

Watch her performance!