Alphabet Soup Challenge - O

The word for o, I came up with a few, but decided on onomatopoeia.  For some reason it was stuck in my head as I remembered hearing a men’s chorus singing it.  Help me out here.  The only group I can think of that would sing it would be Monty Python.  Or Saturday Night Live, the old ones.  Not finding it on my searches, I decided to put on a video of Two Cellos instead. Enjoy!
2Cellos is a Croatian cello duo, consisting of classically trained Luka Šulić and Stjepan Hauser. Signed to Sony Masterworks since 2011, they have released four albums and play instrumental arrangements … Wikipedia 

Members: Luka Šulić, Stjepan Hauser

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