Our themes come with Custom Post Types, for example, Portfolios, Galleries, etc.

Each custom post type has a "slug", or to put it simply: a friendly name for URLs and people to read.

As a default rule we name each slug under the English version of the Custom Post Type. So for example, your URL for a Portfolio post would be something like: http://www.yourdomain.com/portfolio/portfolio-name.

If you wish to alter the name of your post type (for example, if you want instead of "portfolio" to say "work") follow the guide below:

1. Open the respective file under theme_functions/post_types/. The php file you are looking for in most cases has the same name as its CPT, so for Artists it would be theme_functions/post_types/artists.php.

2. Find the piece of code:

$args = array(
		'labels' => $labels,
		'singular_label' => __('Artists Item', 'acoustic'),
		'public' => true,
		'show_ui' => true,
		'capability_type' => 'post',
		'hierarchical' => false,
		'has_archive' => true,
		'rewrite' => array('slug' => 'artists'),
		'menu_position' => 5,
		'supports' => array('title', 'editor', 'thumbnail')		
	);

Notice this line:

'rewrite' => array('slug' => 'artists'),

Convert it as follows:

'rewrite' => array('slug' => 'musicians'),

Notice that "musicians" should be the word that you wish.

Hit save, upload and then go to Settings -> Permalinks in order for your permalinks to be regenerated.

That's all :)