Death, obviously, isn't a possibility. If none of the track fixtures are working then the track and fixtures are probably fine. Since it's connected to lamp wire I'll assume it's plugged into an outlet. Check that there's power to the outlet by plugging in something else there and seeing whether it works; that narrows the field of possible explanations. Assuming you've got power at the outlet, the problem is likely to be somewhere between outlet and track -- could be the plug has been damaged, or a wire has come loose inside the rotary switch, or the rotary switch is broken, or the wire has come loose from a terminal where it connects to the end of the track, or there could be a bad connection between the part of the track that the wire connects to and the track itself.

Thanks. I'll check the parts from plug to fixture. I know there's power because the same outlet will run something else.

But it seems like it would have to be related to the bulb(s) blowing out, because the problem started that instant. Cause or effect.

Do you even know that a bulb blew out? It's not clear from what you've said so far that you're certain about that, since you replaced the bulb(s) to no effect.

Well, thanks. Your first reply led me to the solution. I opened the lamp cord switch and noticed that the ends of the cord inside were black. Cut off a bit, spliced the halves together, and there was light. But yes, one bulb had blown...must have fried the switch.

must have fried the switch.

Quite possible. One failure mode for incandescent bulbs causes them to draw a very large amount of current for a short time. This can burn weak or poor connections open.