generate random basic chord progression

MainWindow.xaml

<Window x:Class="TestApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:TestApp"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Button Content="Generate progression" HorizontalAlignment="Center" Margin="0,210,0,181" VerticalAlignment="Center" Width="136" RenderTransformOrigin="-0.006,0.236" Click="Button_Click" Height="29"/>
        <Label Content="" HorizontalAlignment="Center" HorizontalContentAlignment="Center" Margin="0,70,0,0" Name="chordsTextBox" Height="59" Width="181" FontSize="22" VerticalAlignment="Top"/>

    </Grid>
</Window>

MainWindow.xaml.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace TestApp
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        public Random rand = new Random();

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            List<string> chords = new List<string>();
            int baseNote = rand.Next(12);

            chords.Add(intToChord(baseNote));
            chords.Add(intToChord(baseNote + 7));
            chords.Add(intToChord(baseNote + 2));
            chords.Add(intToChord(baseNote + 4 ) + "m");

            List<string> progression = shuffleProgression(chords);

            // Set the text in the text box to the progression 
            chordsTextBox.Content = String.Join(" ", progression.ToArray());
        }

        private string intToChord(int num)
        {
            List<string> chords = new List<string>() { "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B" };

            if (num > 11)
            {
                while (num > 11)
                {
                    num -= 11;
                }
            } else if (num < 0)
            {
                while (num < 0)
                {
                    num += 12;
                }
            }

            return chords[num];
        }

        private List<string> shuffleProgression(List<string> chordArray)
        {
            List<string> chords = new List<string>();
            int index;

            while (chordArray.Count >= 1)
            {
                index = rand.Next(chordArray.Count);
                chords.Add(chordArray[index]);
                chordArray.RemoveAt(index);
            }

            return chords;
        }
    }
}