MainWindow.xaml

<Window x:Class="NAudioWpfDemo.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="NAudio WPF Demo App" Height="400" Width="800">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="180" />
            <ColumnDefinition Width="456*" />
        </Grid.ColumnDefinitions>
        <ListBox Grid.Column="0" 
                 ItemsSource="{Binding Modules}" 
                 SelectedItem="{Binding SelectedModule, Mode=TwoWay}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Name}" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
        <ContentPresenter x:Name="contentPresenter" Grid.Column="1" 
                          Content="{Binding UserInterface}" />

    </Grid>
</Window>