The singer, who'll be performing at Clive Davis's big pre-Grammy bash, calls motherhood "the best"

Jennifer Hudson, who’ll perform at super-producer Clive Davis’s Pre-Grammy Gala on Saturday night, had a special guest for her rehearsal this week: 18-month-old son David.

“Motherhood is the best,” Hudson, 29, told PEOPLE during a break Thursday, adding that her little one has already caught the showbiz bug. “He is such a little entertainer.”

Decked out in a fluorescent down vest and Pendleton shirt, David spent much of the time bouncing around the ballroom.

But when his mother took the stage to perform an emotional rendition of Aretha Franklin s “Natural Woman,” David was all ears. Once the last note was sung, he pointed at Hudson and said, almost with surprise, “Mama!”

In addition to joining the star-filled guest list at Davis’s party at the Beverly Hilton Hotel, Hudson will take part in a special tribute to Franklin during the Grammys.

The 53rd Annual Grammy Awards will take place Sunday at Los Angeles’s Staples Center and air live on CBS from 8 11:30 p.m. ET/PT.