Just a quick simulation in Algodoo . It's not the best tool to simulate physics because it's not that accurate, the chain is too elastic, but still shows the effect. Here is the saved file if you want to play with it in Algodoo. (The weight on the chain helps the effect but works without it too.)
I've used Speccy for a few years now with great success, but Spectroid looks very good as well. I think I will check it out! Can't have too many spectrum analyzers, lol.