Java - Random nextInt method returning the same integer

I have a bit of code that I am working on. I am stuck on one part of it which involves the Random nextInt() method. This issue I am having is that my code returns the same exact random integer from the index of my arrays. What I am intending to do is iterate through a for loop and, for each of my 16 iterations, I want to have the Random nextInt() method select a string from an array via the index and print that to the screen. At the moment, I am able to generate 1 random string from each index. For the next 15 iterations, my code prints the same random selection instead of randomly selecting a new one.

import java.awt.Color;
import java.util.*;
import java.util.Random;

class Main {
    private int numStrings = 6; 
    private double guitarLength = 28.2;
    private String guitarManufacturer = "Gibson";
    private Color guitarColor = Color.RED; 
    private int musicLength = 16;
    private static int i = 1;
    private static Random rand = new Random();

public Main (){
    this.numStrings = numStrings; 
    this.guitarLength = guitarLength;
    this.guitarManufacturer = guitarManufacturer;
    this.guitarColor = guitarColor;
}

public Main (int strings, double length, String manufacturer, Color color){
     numStrings = strings;
     guitarLength = length;
     guitarManufacturer = manufacturer;
     guitarColor = color;
     System.out.printf("%d, %f, %s, %s", numStrings, guitarLength, guitarManufacturer, guitarColor + "\n");
}

public int getNumStrings() {
  return this.numStrings;
}

public double getGuitarLength() {
  return this.guitarLength;
}

public String getGuitarManufacturer() {
  return this.guitarManufacturer;
}

public Color getGuitarColor(){
  return this.guitarColor;
}

public static void playGuitar(){
    String[] musicNotes = {"A", "B", "C", "D", "E", "F", "G"};
    String[] musicDuration = {"(0.25)","(0.5)","(1)", "(2)","(4)"};
    int index1 = rand.nextInt(musicNotes.length);
    int index2 =  rand.nextInt(musicDuration.length);
     for (i = 1; i < 17; i++){
        System.out.print(musicNotes[index1]);
        System.out.print(musicDuration[index2] + ",");
        }
     }

public static void main (String args[] ){
    Main newGuitar = new Main(6, 24.75, "Les Paul", Color.white);
    playGuitar();
 }
}