SQL SELECT - List rows with matching columns, but remove duplicate column

In my "agenda" database, I have two tables: "sessions" and "speakers".

In my "speakers" table, I have a column labeled "Sessions" that matches the column labeled "Title" in my "sessions" table.

For example:

speakers.Session = "This is my topic title" sessions.Title = "This is my topic title"

I would like to list out all of the sessions, then below each session, list out the speakers belonging to that session.

Here is what I have so far:

    // AGENDA
    function showAgenda($conference) {
        $query = mysqli_query($GLOBALS['con3'],"SELECT CONCAT(speakers.FirstName, ' ', speakers.LastName) SpeakerName, sessions.Title SessionTitle 
                                                FROM sessions 
                                                LEFT JOIN speakers ON sessions.Title = speakers.Session
                                                WHERE Conference LIKE '%$conference%'");
        while($records = mysqli_fetch_array($query)) {
            echo '<strong>'.$records['SessionTitle'].'</strong><br /><br />';
            echo $records['SpeakerName'].'<br /><br />';
        }
    }

The problem with this is that if there are more than two speakers matching a session, it will list that session twice.

Like so:

This is my topic title Speaker 1

This is my topic title Speaker 2

This is another topic title Speaker 3

What I want to happen is:

This is my topic title Speaker 1 Speaker 2

This is another topic title Speaker 3