Create at the root of the theme you want to use, an archive-gaia_media.php file and a single-gaia_media.php file by copying the index.php file. And at the end, create a global-taxonomy-tpl.php file with the following content
<?php
/**
* Template Name: liste par taxonomie
*/
get_header(); ?>
<div id="about-taxonomy">
<section id="pagetitle" class="pagetitle dark" >
<div class="container">
<h1 class="pagetitle-title heading">A propos</h1>
<div id="breadcrumb" class="breadcrumb">
<a class="breadcrumb-link" href="https://www.demos-test.gaia-junior.com/">Home</a>
<span class='breadcrumb-separator'></span><span class='breadcrumb-title'>A propos</span>
</div>
</div>
</section>
<div id="contact" class="contact">
<div class="container">
<h1>Notre Equipe</h1>
</div>
<?php
$gaia_term_list = get_terms(array('taxonomy' => 'genre_mus', 'hide_empty' => true, ));
if ($gaia_term_list > 0):
foreach ($gaia_term_list as $the_term): ?>
<section>
<?php
$arg_taxo_rupt = array(
'post_type' => 'gaia_media',
'posts_per_page' => -1,
'tax_query' => array(
array(
'taxonomy' => 'genre_mus',
'field' => 'slug',
'terms' => $the_term->slug
)
)
);
$req_taxo_rupt = new WP_Query($arg_taxo_rupt);
if($req_taxo_rupt->have_posts()): ?>
<div class="container">
<div style="width: 23%; background-color: #5c5b5b; color: #fff!important;margin-left: 3%; margin-bottom: -30px; border-radius: 3%;padding-left: 1%;">
<h3><?php echo $the_term->name ?></h3>
</div>
<div style="display: flex; justify-content: space-around; margin-bottom: 5%; border: 1px solid #5c5b5b; border-radius: 10px;">
<?php while ($req_taxo_rupt->have_posts()): ?>
<?php $req_taxo_rupt->the_post(); ?>
<article style="margin-top: 2%;">
<div class="panel panel-default">
<?php the_post_thumbnail('medium-large', array('style' => '-webkit-border-radius: 40%; -moz-border-radius: 40%; -ms-border-radius: 40%; -o-border-radius: 40%; border-radius: 40%;')) ?>
<div class="panel-footer">
<h4 class="h4 text-center"><?php the_title() ?></h4>
</div>
</div>
</article>
<?php endwhile; wp_reset_postdata(); ?>
</div>
</div>
<?php endif; ?>
</section>
<?php
endforeach;
endif;
?>
</div>
</div>
<?php get_footer(); ?>