Katy Perry
Birth Name: Catherine Elizabeth Hudson
The "I Kissed A Girl" singer said he decided to look for the stage name as a teenager. She felt a kind of identity crisis and said that names and personalities were created for protection. She thinks she was very frightened by her birth name Katheryn Elizabeth Hudson, but she feels at home with the stage name. I agree!
Rihanna

Birth name: Robin Rihanna Petty
This international pop star is not always known as Rihanna. In fact, Rihanna is actually her middle name. Her name is Robyn, and she confessed in an interview that family and friends still call Robyn to get her attention. She keeps saying that she is tired of listening to Ryan, so she pays attention when someone actually uses her name.
Emma Stone

Birth name: Emily Jean Stone
In an interview in a recent magazine, La La Land actress confessed that she had to change the name, because the industry already had Emily Stone. Changed name to Emma Stone to avoid confusion. Also, most people in the industry actually call it M.
Brad Pitt

Birth Name: William Bradley Pitt
Brad Pitt has always been known as his middle name during his lifetime and his name is actually William. This new star is announced by William at parties and other social events.
Lady Gaga

Birth name: Stephanie Joanne Angelina Germanota
Lady Gaga was actually known as Stephanie Joanne Angelina Germanota before becoming a familiar name worldwide. She adopted the stage name after the famous 1984 queen song "Radio Ga Ga". They say the rest is history.