what is the name of the song in once upon in mexico that el mariachi played in the begining?

Question

the guitar solo.with the guitar that the old man gave him.

Answer 1

It's one of these

"La Culebra"
Traditional
Performed by Mariachi Silvestre Vargas
Under license from Disco Orfeón Videovox S.A./PHAM

"El pájaro cú"
Traditional
Performed by Mariachi Cobre
Under license from Celestial Harmonies