So I need a very specific sort of music, and this seems like the best place to ask.

I need a track of decent length (ideally 3+ minutes, at least), instrumental, with the sound of a ticking clock. It doesn't need to be constant, though that'd be nice. Having a couple instances with at least some prominence would be enough. Dramatic or slow and calm, I can see either working in different ways. The clock and being instrumental (in other words, singing) are the key parts here.

Thanks in advance for any help.