In answer to 'restore moodle from a cron job', I'd say no.
So let's work on fixing the issue.
First check to see if there is a folder in:
/home/barbhall/public_html/learnpianotechnology.com/moodle/theme/
by myoldertheme.
If there is, move it out of that folder to another location ... like /home/barbhall/
If there is not, then suggest doing this to *possibly* get by the issue for now:
In config.php add the following line:
$CFG->theme='clean';
The clean theme is one of the two themes that come with version 2.9 of Moodle.
No need to reboot/restart anything, just open a browser and before you attempt to access your site clear browser cache.
Then see if you can get to your site.
If you cannot, then it might be that the server has cached the old theme ...
Attempt going directly to: http://yoursite/[pathtomoodleifneeded]/admin/purgecaches.php
That should prompt you to login and it should re-direct to the php file given above.
'spirit of sharing', Ken