def getArtists(tracks):
    """
    Returns distinct artists names from the specified tracks.

    The names are sorted alphabetically.

    Tracks is expected to be an [] of Track

    Result example: [artistName1, artistName2, ...]
    """
    artists = []
    if tracks:
        for track in tracks:
            artist = track.artist
            if not artist in artists:
                artists.append(artist)
    return sorted(artists)