AxWindowsMediaPlayer1.URL = "e:song.mp3"
AxWindowsMediaPlayer1.Ctlcontrols.play()
AxWindowsMediaPlayer1.settings.rate = 0.5

If (player.settings.isAvailable("Rate")) Then
    player.settings.rate = 0.5
End If

Dim mpMediaPlayer As New MediaPlayer.MediaPlayer
mpMediaPlayer.FileName = "e:song.mp3"
mpMediaPlayer.Rate = 0.5
mpMediaPlayer.Play()