about names, used as an act?

People take stage names to maintain privacy, but also sometimes because of union rules.  In the stage actors union anyway, they will only allow one person with a particular name.  So if there are two actors with the same name, the second one to join will have to modify his/her stage name.  The first person named Joe Smith can be Joe Smith.  But the second person named Joe Smith might have to use his middle name like Joe William Smith.  Then the next guy name Joe Smith might decide to use his mother's maiden name instead of his birth name, like Joe Jones.  Etcetera and so forth. 

Other times, it's to allow a certain anonymity. 

Other times, it's because their given name sounds odd or may be off-putting.  For instance, if you were a folk singer with the last name Hitler, you might want to consider using a stage name. 

Sometimes people use a stage name to release a second sort of sound.  Jimmy Buffett did that with an experimental album that he didn't want people to be confused with his usual sound.  Another example is the Garth Brooks/Chris Gaines releases. 

Tons of reasons.  Shoot.  We use handles here on Chordie.  I doubt your given name is Gitaardocphil.