Rey mysterio entrance song?
Rey Mysterio entrance theme song is Booyaka 619 by P.O.D.His old theme song is called 619
No Rey Mysterio Jr. is not Rey Mysterio. Rey Mysterio is the one who trained rey mysterio Jr. Rey Mysterio is rey myserio Jr.'s uncle You are partly right in that Rey Mysterio, Sr. did train Rey Mysterio, Jr. BUT Rey Mysterio, Jr. has dropped the Jr. off of his name is known as Rey Mysterio. So in that regard you are wrong.
Rey Misterio (same person as Rey Mysterio) was a luchador in Mexico, and also the uncle of WWE's Rey Mysterio Jr., who changed his ring name to Rey Mysterio. The reason was because fans hadn't heard of his uncle so there was no use for the "Jr." and if you want to know more about rey mysterio, read his new book, Behind The Mask