A custom template file is not properly rendered I know this issue is covered quite well, but at the moment I'm really perplexed on this.    

First, I'm using the Zen theme. In my template folder I've created page-music.tpl.php, page-gallery.tpl.php, page-bio.tpl.php, page-front.tpl.php, and so on. I've tried putting the code in the template.php for the custom pages, but I can't redefine the zen_preprocess_page() function. The custom pages won't render the admin menu module, or display the modules properly for that matter. The JavaScript code is all funky.

I'm not sure if I'm using the right code for the the template.php. There seems to be a lot of jumbled imformation on this matter.
If you have path like contact then the page-contact.tpl.php will be automatically available (view the theming documentation).

You can also declare your own tpl with this code (put this in a custom.module):

function custom_menu() {
  $items = array();
  $items['contact'] = array(
    'title' =&gt; 'Contact us',
    'page callback' =&gt; 'custom_make_section',
    'access arguments' =&gt; array('access content'),
    'type' =&gt; MENU_NORMAL_ITEM,
  );
  return $items;
}

function custom_make_section() {
  return;
}


Also a little bit easier is using the module Empty Page in order to create the custom paths you want and then these paths will provide the page-....tpl.php you need.