Commercial Calamity

A local construction company has a commercial on the radio that is just plain wrong.  There's some fake dialogue about how awesome the construction company is, followed by the actual advertising message.  During this part, while the narrator talks about how wonderful the construction company is, there is a low beat that starts out slow and accelerates, with the net effect of making you really, really nervous.  On the surface, they sound really great, but thanks to this tension their commercial has implanted into my mind, I would never in a million years use them.