How do I query for a post by custom field?

I have a custom field called “song-id” and I’d like to lookup a post by a song-id value. Can someone give me the code snippet for it?

(bonus: also looking for a code to use the permalink in the post to redirect to that page)

$songQuery = new WP_Query('meta_query' => array(
    array(
        'key' => 'song-id',
        'value' => 'song id value here',
        'compare' => '='
    )
));

You can use above code to query with custom field then use loop to get the contents.