Why do some celebrity singers have their original names and use pseudonyms? How to use it?

It’s not a pseudonym, it’s a stage name. The original name is not good for the type of career the star is involved in. It can also be called a code name! Having a good name will make people's eyes shine. Some celebrities' original names are very traditional and popular, and they don't give people a special feeling. For example, Jackie Chan means to be the dragon among men, and his original name is Chen Gangsheng. Most of these names Everyone will use it. The surname Chen was born in Hong Kong and does not have the confidence to be popular.