You could fish a new run and put the new boxes where you want them. Then you either rip out the old cable or abandon it in place, and patch the old ceiling holes.

A shortcut I've seen used in years past is to put covers on some of the boxes and paint them, and then put a track over the row of covers to more or less hide them. Maybe you could find pendants that fit a track? (I don't know for sure, as I don't do that kind of lighting.)

Or you could just decide that having the lights a foot off center is something you'd get used to after a few weeks. That's what I'd probably do. ;-)

Thanks for the ideas. I've got a week or two to decide.

Depending how far you want to move it, you might try one of these:

Here is a link that might be useful: Medallions

Bingopin...interesting idea. Thanks.

In the past, when I've had to deal with pendant lights in the wrong place, like getting a new shape of kitchen table, I've gotten a nice enamelled screw-in hook, installed it securely (by finding a joist or using a moly bolt) where I want the light to hang, and then had the wire come from the electrical box to the hook in a graceful loop, and then straight down.

kudzu9, thanks...that's definitely one of the most likely fixes.