The guests are at the wedding. They attend the wedding, but they are not active participants.
For musical concerts, a member of the audience would say, “I’m at the concert.” A performing musician could say she was in the concert: “I’ll be in the concert tonight; I play guitar for the opening band.”
///Manciu cu Fabrica de staruri
vreau in Japonia, Zidu’
vreau sa ating o panda
vreau un robot care sa-mi tina de urit
*( nunta celor care se ocupa cu muzica