chime in

JT Onlineにあったchime（鐘，チャイム）に関する記事の見出しです。本文は全文引用するには長かったのでカットしました。興味のある方はURLをクリックしてください。
Everyone chime in . . .
Classes start early on our island — 6 a.m. every day, even on Sundays. At least that's what any teacher visiting for the first time would think. This is because there is a "chime" that sounds over the island's PA system at 6 a.m., which lets islanders know that it is time to wake up. The chime happens to be the same one used in public schools throughout Japan to indicate the beginning and end of classes.
Chimes, still heard in the countryside in Japan, are a hangover from the past when people didn't have watches and spent their days in the fields harvesting rice and vegetables. Farmers had to wake up early to tend their fields in the cool of the morning. The chime sounded again at 12 for lunch, a signal for everyone to stop working, sit down under the shade of a tree, and eat their obento lunch. The 5 p.m. chime indicates the working day is finished. The chime sounds one last time at 9 p.m. indicating it is time for bed. Early to bed, early to rise.
http://search.japantimes.co.jp/cgi-bin/fl20101120cz.html
chime inには「会話に横から口をはさむ、相づちを打つ」や「（…と）調和[合致]する」（『スーパーアンカー英和辞典』第4版，学研教育出版）という意味があり，記事の後半に出てくるsynchronicityからもわかるように，今回は後者の意味で用いられています。
また，『プログレッシブ英和中辞典』（小学館）によれば，fall into chime with（…と一致する），keep chime with（…と調子を合わせる）のように，chime(n.)には堅い文語表現で「（…との）調和, 一致｟with ...｠」という意味があり，このことからもchimeには「同調」という語義があることがわかります。（院生 小山本）