Crossword clue: a mock serenade of discordant noises, made with kettles, tin horns, etc., designed to annoy and insult.
1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
a noisy mock serenade (made by banging pans and kettles) to a newly married couple