Add second id in post by costume field

Hello to everyone

Is it possible to define costume field as second id of post.

I want to echo fields of post not with id of a post, but with my cotume field id

This code take field with post id

<?php $id = 6501; $temp = $post; $post = get_post( $id ); setup_postdata( $post ); ?>
  <a href="<?php the_permalink() ?>" target="_blank">
	<?php echo get_post_meta($post->ID, 'title', true); ?>
	<?php echo get_post_meta($post->ID, 'artist', true); ?>
  </a>
<?php wp_reset_postdata(); $post = $temp; ?>