add_filter( 'gform_pre_render_4', 'freetrial_studios' );
add_filter( 'gform_pre_validation_4', 'freetrial_studios' );
add_filter( 'gform_pre_submission_filter_4', 'freetrial_studios' );
add_filter( 'gform_admin_pre_render_4', 'freetrial_studios' );
function freetrial_studios( $form ) {

foreach ( $form['fields'] as &$field ) {

    if ( $field->type != 'select' || strpos( $field->cssClass, 'studio-list' ) === false ) {
        continue;
    }

    // Get the ID of post
    $studio_id = get_the_ID();
    $studios = get_field('field_557a974776dd2', $studio_id);


    if( $studios ) {

        $studio_title = get_the_title( $studio_id );
        $studio_meta = get_post_custom($studio_id);
        $choices = array();


        $locations = array();
        $p = get_post(); // gets the basic post details
        $f = get_fields(); // gets the ACF details
        $m = array_merge((array)$p, (array)$f); // merges all details into one array
        array_push($locations, $m);


        foreach ( $studios as $studio ) {

            echo '<pre>';
                print_r( get_field('field_557a974776dd2', $studio_id, false) );
                echo '....';
                print_r( get_the_title( $studio_id ) );
                echo '....';
                print_r( the_title( $studio_id ) );
                echo '....';
                print_r( $studio_meta );
                echo '....';
                print_r( $m );
                echo '....';

            echo '</pre>';

            // Populate the drop down field with values
            $choices[] = array( 'text' => $studio, 'value' => $studio );
            $field->choices = $choices;
        }

        $field->placeholder = 'Select a Studio';
        $field->choices = $choices;
    }
}
return $form;
}

Array
 (
  [0] => 102
  )
  ....Free trial form 2....113Free trial form 2....Array
 (
[_edit_lock] => Array
    (
        [0] => 1437533210:2
    )

[_edit_last] => Array
    (
        [0] => 2
    )

[_wp_page_template] => Array
    (
        [0] => default
    )

[studio_list] => Array
    (
        [0] => a:1:{i:0;s:3:"102";}
    )

[_studio_list] => Array
    (
        [0] => field_557a974776dd2
    )

[email_address] => Array
    (
        [0] => email@gmail.com
    )

[_email_address] => Array
    (
        [0] => field_55add0bd111c1
    )

 )
 ....Array
(
[ID] => 113
[post_author] => 2
[post_date] => 2015-07-21 14:53:03
[post_date_gmt] => 2015-07-21 04:53:03
[post_content] => Form id 4

[gravityform id="4" title="false" description="false" ajax="true"]
[post_title] => Free trial form 2
[post_excerpt] =>
[post_status] => publish
[comment_status] => open
[ping_status] => closed
[post_password] =>
[post_name] => form-2
[to_ping] =>
[pinged] =>
[post_modified] => 2015-07-22 12:38:31
[post_modified_gmt] => 2015-07-22 02:38:31
[post_content_filtered] =>
[post_parent] => 21
[guid] => http://website.com.au/?page_id=113
[menu_order] => 0
[post_type] => page
[post_mime_type] =>
[comment_count] => 0
[filter] => raw
[studio_list] => Array
    (
        [0] => 102
    )

[email_address] => email@gmail.com
)
....