When the user clicks the Play button, the program sets the control's FileName property to the name of the MIDI file, sets Wait to True so the control opens the file synchronously, and sets Command = Open to open the file. It then sets Command = Play to play the file. It does not set Wait = True first so the play is asynchronous.

When the control finishes playing, the program closes the file and re-enables the Play button.

Private Sub Form_Load()
    txtFilename.Text = App.Path
    If Right$(txtFilename.Text, 1) <> "\" _
        Then txtFilename.Text = txtFilename.Text & "\"
    txtFilename.Text = txtFilename.Text & "Passport.mid"

    ' Prepare the MCI control for WaveAudio.
    MMControl1.Notify = False
    MMControl1.Wait = True
    MMControl1.Shareable = False
    MMControl1.DeviceType = "Sequencer"
End Sub

' Open the device and play the sound.
Private Sub cmdPlay_Click()
    cmdPlay.Enabled = False

    ' Set the file name.
    MMControl1.FileName = txtFilename.Text

    ' Open the MCI device.
    MMControl1.Wait = True
    MMControl1.Command = "Open"

    ' Play the sound without waiting.
    MMControl1.Command = "Play"
End Sub

' Close the device.
Private Sub MMControl1_Done(NotifyCode As Integer)
    MMControl1.Command = "Close"
    cmdPlay.Enabled = True
End Sub