Trying to print array within my code in java

I have two separate files named Guitar and TestGuitar trying to execute code to get the number of strings, guitar length, make, color and then 16 randomly selected musical notes and durations. I can get my code to compile and execute but cannot figure out how to have it print the information in my playGuitar() section of the Guitar code. Any ideas or input on how to move forward would be very helpful and appreciated. This is the first code for Guitar.java

/*
* File: Guitar.java
* Author: 
* Date: Feb 8, 2020
* Purpose: 
*/

import java.util.Random;

public class Guitar {    
    private int numStrings;
    private double guitarLength;
    private String guitarManufacturer;
    private String guitarColor;

    //Constructor
    public Guitar(int numStrings, double guitarLength, String guitarManufacturer, String guitarColor) {
    this.numStrings = numStrings;
    this.guitarLength = guitarLength;
    this.guitarManufacturer = guitarManufacturer;
    this.guitarColor = guitarColor;
    }

    // Default Constructor
    public Guitar() { 
    this.numStrings = 6;
    this.guitarLength = 28.2;
    this.guitarManufacturer = "Gibson";
    this.guitarColor = "Red";
    }

    // Setter methods 
    // setnumStrings
    public void setnumStrings(int numStrings) {
    this.numStrings = numStrings;
    }
    // setguitarLength
   public void setguitarLength(double guitarLength)  {  
    this.guitarLength = guitarLength;
    }
    // setguitarManufacturer
   public void setguitarManufacturer(String guitarManufacturer)  {  
    this.guitarManufacturer = guitarManufacturer;
    }
    // setguitarColor
   public void setguitarColor(String guitarColor)  {    
    this.guitarColor = guitarColor;
    }

   // Getter methods
   // getnumStrings
    public int getnumStrings() {
    return numStrings;
    }    
    // getguitarLength
    public double getguitarLength() {
    return guitarLength;
    }
    // getguitarManufacturer
    public String getguitarManufacturer() {
    return guitarManufacturer;
    }
    // getguitarColor
    public String getguitarColor() {
    return guitarColor;
    }

    // playGuitar method for 16 randomly selected musical notes
    public String playGuitar() {
String play = "[";
//arrays containing possible notes and duration
char[] notes = {'A','B','C','D','E','F','G'};
double[] duration = {0.25,0.5,1,2,4};
//integers works as index for the arrays above
int a;
int b;
//initiate a random number
Random rn = new Random();
//for loop to select 16 randomly selected musical notes of random duration
for (int k=0;k<16;k++) {
    a = rn.nextInt(7);
    b = rn.nextInt(5);
    play = play + notes[a] + "(" + String.valueOf(duration[b]) + ")";
    if (k!=15) { 
        play = play + ",";
    }
}
play = play + ']';
System.out.println(play);
return play; 
}

    // toString method
    public String toString() {
    return "toString(): (numStrings = " + numStrings + ", guitarLength = " + 
    guitarLength + ", guitarManufacturer = " + guitarManufacturer + 
    ", guitarColor = " + guitarColor + ")";
}
    }

This is the second part of code TestGuitar

/*
* File: TestGuitar.java
* Author: 
* Date: Feb 8, 2020
* Purpose: 
*/
import java.util.Random;

public class TestGuitar extends Guitar{ 
public TestGuitar(int numStrings, double guitarLength, String guitarManufacturer, String guitarColor) {
super(numStrings, guitarLength, guitarManufacturer, guitarColor);
} 
public static void main(String[] args) {
Guitar one = new Guitar(7, 30.2, "Fender", "Black");
System.out.println(one.toString());
System.out.println("getNumStrings(): " + one.getnumStrings());
System.out.println("getGuitarLength(): " + one.getguitarLength());
System.out.println("getGuitarManufacturer(): " + one.getguitarManufacturer());
System.out.println("getGuitarColor(): " + one.getguitarColor());
}


}