In 1876, Grieg created incidental music for the premiere of Ibsen's play 'Peer Gynt', at the request of the author. Many of the pieces from this work became very popular in the form of orchestral suites or piano and piano-duet arrangements.
'At the Wedding' is not included in one of the suites. It’s the very beginning of the incidental music and now transcribed for Symphonic Band by Jos van de Braak.