Visual Basic.NET - cargar, filtrar y escuchar audios

Imports System.Windows

Public Class Form1

    Dim MiExplorador As OpenFileDialog

    Private Sub BAgregar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BAgregar.Click

        MiExplorador = New OpenFileDialog

        MiExplorador.Filter = "Audio|*.mp3|Video|*.mp4"

        MiExplorador.Multiselect = True

        If (MiExplorador.ShowDialog() = DialogResult.OK) Then

            For Each Archivo As String In MiExplorador.FileNames

                ListBox1.Items.Add(Archivo)

            Next

        End If

        MiExplorador.Dispose()

    End Sub

    Private Sub ListBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListBox1.SelectedIndexChanged

        AxWindowsMediaPlayer1.URL = ListBox1.SelectedItem

    End Sub

End Class

Dim MiBuscados() As Integer

    Private Sub BuscarTodos(ByVal ABuscar As String, ByRef IndexDeLosBuscados() As Integer)

        Dim Index As Integer = -1

        Dim i As Integer = 0

        ReDim MiBuscados(LBMedias.Items.Count)

        For Each S As String In LBMedias.Items

            If S.IndexOf(ABuscar) > -1 Then

                IndexDeLosBuscados(i) = LBMedias.Items.IndexOf(S)

                i += 1

            End If

        Next

    End Sub