Ariana Grande: 'Alvin & The Chipmunks' Performance!

Ariana Grande hits the stage inside the El Rey Theatre to perform at the Alvin and the Chipmunks: Chipwrecked Blu-ray and DVD release party on Monday (March 26) in Los Angeles.

The 18-year-old actress/singer tweeted, “Had so much fun singing at the Chipmunks premier today!.. Now having dinner with my friends & family. How are you all? Xoxo :]”

PHOTOS: Check out the latest pics of Ariana Grande

The DVD is out on shelves NOW — and at Wal-mart you’ll find even more merchandise — a spring children’s apparel line which includes several licensees that provide T-shirts, pajamas, swimwear, sportswear and swimwear, as well as hosiery and headwear.

10+ pics inside…