Which intrument did Lady Gaga began to play at the age of four?

Explanation

Stefani Joanne Angelina Germanotta was born on March 28, 1986 and is better known by her stage name Lady Gaga. She was born and raised in New York City. Lady Gaga studied at the Convent of the Sacred Heart and briefly attended New York University's Tisch School of the Arts before withdrawing to focus on her musical career. In 2007, record executive and producer Vincent Herbert signed her to his label Streamline Records, an imprint of Interscope Records. Initially working as a songwriter.