Man serenades grandmother with Nat King Cole's 'Unforgettable' on 98th birthday

(INSIDE EDITION) - A 98-year-old woman was overcome with emotion as her grandson serenaded her with Nat King Cole's "Unforgettable" on her birthday.

Grandma Gina Rosa Offord DiSanto Evangelista Ciasco of north Florida could be seen enjoying the song while wiping away tears in a video her grandson Ash Ruiz posted to Facebook.

Ruiz, a former member of Puerto Rican boy band Menudo, told he and his grandmother have held onto a tradition of singing Nat King Cole songs together since he was 8 years old, when Grandma Gina taught him to sing "Unforgettable" for the first time.

"Having a grandmother that was always singing, that was really powerful," he said. "It's kind of like I started singing before I started talking."

Inspired by his Grandma Gina, he joined the band when he was 14 years old and began touring the world, but still remained close to his family.

Every year, they sang "Unforgettable" together for her birthday until Grandma Gina started losing her ability to sing at 80 years old.

From then on, Ruiz says he sings the song to her every year, and when he moved to Boulder, Colo., he continued the tradition over the phone and on Skype.

This year, he happened to be in Florida for a rehearsal and drove to her home to surprise her for her birthday.

"Her body's in that place of winding down, so she can barely speak," Ruiz explained. "But one thing that was so beautiful to notice was her presence, and her spirit was really bright and really alive and really receptive. When I started singing her favorite song to her, she just started crying."

Ruiz says that he wouldn't have pursued a singing career if it wasn't for his grandmother.

"Me and my grandmother have always had a really beautiful relationship," Ruiz recalled. "She was the kind of grandmother that was always challenging me to see things a bit differently. Singing has always been a part of my experience and I really owe it to my grandmother."