Posts with different line spacings?

Yes you can, but it’s going to take a little custom work on the theme.

The first thing you’ll want to do is to modify the loop to add a specific CSS class to your different types of posts.

One way to do this would be to add the posts’ category slugs to their wrappers. For instance, if the loop looks something like:

<?php
if(have_posts()) : while(have_posts()) : the_post();
?>
<div class="post">
  <h2><?php the_title(); ?></h2>
  <?php the_content(); ?>
</div>
<?php
endwhile; endif;
?>

You could change it to looks something like:

<?php
if(have_posts()) : while(have_posts()) : the_post();
?>
<div class="post <?php echo wp_get_object_terms($post->ID, 'category'); ?>">
  <h2><?php the_title(); ?></h2>
  <?php the_content(); ?>
</div>
<?php
endwhile; endif;
?>

Note: I haven’t used the wp_get_object_terms() function before, so I’m not 100% certain if the code above will work as expected.

The next thing you’ll need to do is edit the style.css file to assign a slightly different style to the posts based on the class you added. For instance, if the classes that were added were “prose” and “poetry”, you could simply add something like:

.poetry {
line-height: 1.1em;
}
.prose {
line-height: 1.5em;
}

or however you would like the style changed.

Good luck.

Question: Is it possible to add something to the code for each paragraph to affect line spacing like you can change font and font size?