error CS1061: 'GameObject' does not contain a definition for 'tune'

Questions & Answers
1

I am making a note wheel to help teach music. I change the letters by referencing an array, but this has caused the sharps and flats to not follow the letters. To fix this I am trying to take the sharps and flats from the other letters on the wheel, but I am getting this error:
Assets\Rotate.cs(65,35): error CS1061: ‘GameObject’ does not contain a definition for ‘tune’ and no accessible extension method ‘tune’ accepting a first argument of type ‘GameObject’ could be found (are you missing a using directive or an assembly reference?)

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;

public class Rotate : MonoBehaviour
{
    public string display;
    public static int turn;
    public int letter;
    public int tune;
    string[] noteArray = { "D", "E", "F", "G", "A", "B", "C", "D♯", "E♯", "F♯", "G♯", "A♯", "B♯", "C♯", "D♭", "E♭", "F♭", "G♭", "A♭", "B♭", "C♭" };
    public TextMeshProUGUI note;
    public float current = 0;
    public GameObject[] AllNotes;
    public int indentify;
    int indentification;
    public int nextTune;



    void Start()

    {
        display = noteArray[letter + (7 * tune)];
        note.text = display;
    }
            
    

    void Update()
    {

        tune = nextTune;
        if (current == 1)
        {
            turn = 0;
            current = 0;
        }
        if (turn != 0)
        {
            current = current + 1;

            letter = letter - turn;

            if (letter == 7)
            {
                letter = 0;
            }
            if (letter == -1)
            {
                letter = 6;
            }

            indentification = indentify - turn;
            if (indentification == 7)
            {
                indentification= 0;
            }
            if (indentification == -1)
            {
                indentification = 6;
            }
            var noteBefore = AllNotes[indentification];
            nextTune = noteBefore.tune;

        }
    }


    public void Retune()
    {
        tune = tune + 1;
        if (tune == 3)
        {
            tune = 0;
        }
        display = noteArray[letter + (7 * tune)];
        note.text = display;
    }
}
2

This is straightforward : GameObject indeed does not have tune : it is in class Rotate .
So you either have to change array type to public Rotate[] AllNotes;, or write nextTune = noteBefore.GetComponent<Rotate>().tune;