Saxophone included.

Jennifer Garner Playing Sax Reese Witherspoon
Credit: Instagram/Jennifer Garner

There's something special about a friend calling you up at midnight to serenade you with a birthday tune – but what about when that friend is Jennifer Garner, and she can play the sax?

Jennifer gave her fans a fun look into one of her hidden talents on Thursday when she posted a video on Instagram showing off her saxophone skills, giving us all major #ThrowbackThursday memories to high school band years. The post's caption indicated that she was playing the "Happy Birthday" song in honor of her longtime gal-pal Reese Witherspoon, who turns 42 on March 22. See the fun moment from Jennifer below:

The Texas-born, West Virginia-raised actress marched into the frame in full uniform – plumed hat, gloves, and spats included – turned on her heels, and raised her instrument. And, of course, she tooted out a charming rendition of the classic birthday tune. She even included a soulful "And many more....." riff at the end of her solo. With a smile to the camera, she turned and marched away.

WATCH: Jennifer Garner's Southern Living Interview

We can only imagine what it's like to get such a unique and thoughtful birthday performance from Jennifer Garner. Her form! The clarity of her notes! It's just another reason why this Southern Mama is one of our favorite stars to watch.