“Begin on the spot! The Mystery, the Mystery at once!” shouted the audience, the shrill voice of Joannes de Molendino sounding above all the rest, and piercing the general uproar like the fife in a charivari at Nimes.

I don't have my dictionary on this computer, so I've got to search for definition, and the edit it in.

charivari [ˌʃɑːrı'vɑːrı], shivaree, esp. U.S. chivaree
noun
1 a discordant mock serenade to newlyweds, made with pans, kettles, etc.

2 a confused noise; din
[ETYMOLOGY: 17th Century: from French, from Late Latin caribaria headache, from Greek karebaria, from kare head + barus heavy