Single page has 404 Error

Hi all. I run MumsonFans.com and randomly out of nowhere today my Music page (http://mumsonfans.com/music) gave me a 404.Not even a custom 404, but a GoDaddy 404 page.

If I change my permalinks to default the page works. If I change it back, it does not. I disable all plugins, tested, enabled, tested, and nothing. I don’t want to change my permalinks to default.

I have tried everything I read on the support forms and one thing has worked. When I go into MyPHPAdmin and into my database, under wp_options for home if I change the URL to http://mumsonfans.com/sub-directory then the page works again. I tried changing it back and it goes back to not working.

I’ve read up on what this option is but I’m not confident I understand. I’m worried what this might do overall to the site. It has been established for some time and I get most of my traffic from Google so I am trying to solve this without messing up any possible current URLs or site traffic.

Thank you!

Edited to add: So far this seems to be the only page affected for some reason.