function my_em_add_default_tickets($tickets, $EM_Bookings) {
    
    if ( empty($tickets->tickets) ) {
        $ticket_data = array();
        
        $ticket_data[0] = array( 'ticket_name' => 'General Admission', 'ticket_spaces' => 10, 'ticket_price' => 450, 'ticket_min' => 0, 'ticket_max' => 5 );
		$ticket_data[1] = array( 'ticket_name' => 'Section A', 'ticket_spaces' => 10, 'ticket_price' => 550, 'ticket_min' => 0, 'ticket_max' => 5 );
        
        foreach ($ticket_data as $ticket) {
            
            $EM_Ticket = new EM_ticket();
            $EM_Ticket->ticket_name   = $ticket['ticket_name']; 
            $EM_Ticket->ticket_spaces = $ticket['ticket_spaces']; 
            $EM_Ticket->ticket_price = $ticket['ticket_price'];
			$EM_Ticket->ticket_min = $ticket['ticket_min'];
			$EM_Ticket->ticket_max = $ticket['ticket_max'];
            
            $tickets->tickets[] = $EM_Ticket;
        }
    }
    
    return $tickets;
}
add_filter('em_bookings_get_tickets', 'my_em_add_default_tickets', 100, 2);