Come effettuare un passaggio di valori tra 2 classi?

Ciao a tutti, sono nuovo, ho appena letto i regolamenti pertanto spero di non violare alcuna regola del forum. Espongo il mio problema:

ho le seguenti due classi e dovrei effettuare il passaggio della stringa tempo e timbro ad un'altra classe in modo da poterla modificare li.ho creato il metodo getTempo() ma non so come chiamarlo correttamente nell'altra classe.

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.*;
import java.util.*;

public class LetturaFile {

 public  LetturaFile() throws Exception {
        FileInputStream in = new FileInputStream("/Users/giuseppecaponetto/Desktop/prova.txt");
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        
        
 
        File file =new File("/Users/giuseppecaponetto/Desktop/prova.txt");
 
             
 
        FileReader fr = new FileReader(file);
        LineNumberReader lnr = new LineNumberReader(fr);
 
        int linenumber = 0;
 
        while (lnr.readLine() != null){
                  linenumber++;
         }
 
        System.out.println("Total number of lines : " + linenumber);
 
        lnr.close();
                 
                 
        String strLine;
        String[] mioarray;
        mioarray = new String[linenumber];
        String note = "";
        String stringreplacer = "";
             
         for (int j = 0; j < linenumber; j++){
                    mioarray[j] = br.readLine();
                                            }
          for (int i = 0; i < linenumber; i++){         
                   System.out.println(mioarray[i]);
                                                      }
            for (int z = 3; z <linenumber; z++){
                   note = note + mioarray[z];
                   }
        String subnotes = note.substring(5);
        String notepulite = subnotes.replaceAll(" \\\\", stringreplacer); 
        System.out.println(notepulite);//note con la virgola come separatore
        String[] arraynote = notepulite.split(",");
                     
        System.out.println(arraynote[7]);//l'indice dell array parte da zero!
        String tempo = mioarray[1].substring(6);
        String timbro = mioarray[2].substring(7);
        
        
}
    public String getTempo(){
        return tempo;
    }
  
}

ecco la classe in cui dovrei chiamarlo:

import javax.sound.midi.Instrument;
import javax.sound.midi.MidiChannel;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Patch;
import javax.sound.midi.Soundbank;
import javax.sound.midi.Synthesizer;
import java.io.*;

public class OpenInstrument  {
    
    Synthesizer synth;
    MidiChannel channels[];
    Soundbank bank;
    Instrument instrs[];
    Instrument myInstrument;
    Patch myPatch;
    
         
    
    OpenInstrument() {
        try
                {
                        // Locate the default synthesizer
                        synth = MidiSystem.getSynthesizer();
                        // Open the synthesizer
                        synth.open();
                        // Get the available Midi channels - there are usually 16
                        channels = synth.getChannels();
                        // Get the synth's soundbank where all the sounds are stored
                        bank = synth.getDefaultSoundbank();
                    // Load all the available instruments
                        synth.loadAllInstruments(bank); 
                    // Get a list of the available instruments
                        instrs = synth.getLoadedInstruments();
                }
        catch (Exception exc)
        {
            exc.printStackTrace();
        }
    }
    
    public void PrintInstrumentList() {
        for (int i = 0; i < instrs.length; i++) {
                    System.out.println(i + ") " + instrs[i].getName());
                }
    }
    
    public void SetInstrument(int instrumentNum, int channelNum) {
        myInstrument = instrs[instrumentNum];       
        // Get the information describing the instrument - the
                // patch contains the soundbank and program number
                myPatch = myInstrument.getPatch();
        // Set a channel to use the guitar instrument
                channels[1].programChange(myPatch.getBank(),myPatch.getProgram());
    }
    
    public void PlayChord() {
        try {
            // Play a chord on channel 1
            int basekey = 60;//do medio
            int tempo = 100;//in millisecondi
            channels[1].noteOn(60, 127); //c
            Thread.sleep(tempo);
            channels[1].noteOn(47, 127); //B
            Thread.sleep(tempo);
            channels[1].noteOn(52, 127); //E
            Thread.sleep(tempo);
            channels[1].noteOn(55, 127); //G
            Thread.sleep(tempo);
            channels[1].noteOn(59, 127); //B
            Thread.sleep(tempo);
            channels[1].noteOn(64, 127); //E
            // Give the notes some time to play
            Thread.sleep(tempo);
            // Turn the notes off
            channels[1].allNotesOff();
                }
        catch (Exception exc)
        {
            exc.printStackTrace();
        }
    }
    

    
    public void close() {
        // Close the synthesizer device
                synth.close();
    }
    
    



}