Add paragraph to header

Probably.

Look for this in the header.php

// Add the blog description for the home/front page.
	$site_description = get_bloginfo( 'description', 'display' );
	if ( $site_description && ( is_home() || is_front_page() ) )
		echo " | $site_description";

and underneath it put something like

?> (to switch to html)
<p id="header-text"> Any text you like </p>

<?php (to go back to php)

Then you can style the new paragraph however you like using #header-text in your css

Sorry ignore what I just said. I’ve got my idiot head on today

Do this instead

find
<div id="site-description"><?php bloginfo( 'description' ); ?></div>

and add underneath something like

<p id="header-text">Any text you like</p>

Then you can style the new paragraph however you like using #header-text in your css

Great, thanks! Lucky the client won’t need to change it.