Использование GridBagLayout

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BorderFactory;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.border.LineBorder;
 
 
public class theoryN extends JFrame{
final JPanel content = new JPanel(new GridBagLayout()); 
JLabel header = new JLabel(new javax.swing.ImageIcon("https://www.cyberforum.ru/images/header.jpg"));
 
static int iOct=0;
JLabel sKey = new JLabel();
ImagePanel sKeyPic = new ImagePanel("https://www.cyberforum.ru/images/Snote_stan.jpg");
NotePaint Note = new NotePaint();
JLabel sKeyInfo = new JLabel("sKeyInfo");
String[] Sskey = {"До", "Ре", "Ми", "Фа", "Соль", "Ля", "Си" };
String[] Ssokt = {"Первая", "Вторая"};
JComboBox Sscb = new JComboBox(Sskey);
JComboBox SsOktcb = new JComboBox(Ssokt);
 
 
public  theoryN(){
super("");
sKey.setFont(Config.font_16);
sKey.setText("Скрипичный ключ");
sKey.setIcon(new javax.swing.ImageIcon("https://www.cyberforum.ru/images/Skey.jpg"));
 
 
content.add(header, new GridBagConstraints(0, 0, 2, 1, 100, 0, GridBagConstraints.FIRST_LINE_START,
            GridBagConstraints.HORIZONTAL, new Insets(0, 0, 0, 0), 0, 0));
header.setBorder(BorderFactory.createLineBorder(Color.yellow));
 
content.add(sKey, new GridBagConstraints(0, 1, 1, 1, 47, 0, GridBagConstraints.FIRST_LINE_START,
            GridBagConstraints.NONE, new Insets(5, 5, 5, 5), 0, 0));
sKey.setBorder(new LineBorder(Color.GREEN, 2));
 
content.add(sKeyPic, new GridBagConstraints(1, 1, 1, 2, 50, 120, GridBagConstraints.NORTH,
            GridBagConstraints.BOTH, new Insets(5, 5, 5, 5), 0, 0));
 sKeyPic.setLayout(new BorderLayout());
 sKeyPic.add(Note);
 
sKeyPic.setBorder(new LineBorder(Color.RED, 4));
 
content.add(sKeyInfo, new GridBagConstraints(0, 2, 1, 2, 0, 0, GridBagConstraints.NORTH,
            GridBagConstraints.NONE, new Insets(5, 5, 5, 5), 0, 0));
 
content.add(Sscb, new GridBagConstraints(1, 3, 1, 1, 50, 0, GridBagConstraints.NORTH,
            GridBagConstraints.NONE, new Insets(5, 5, 5, 5), 0, 0));
content.add(SsOktcb, new GridBagConstraints(1, 3, 1, 1, 50, 0, GridBagConstraints.NORTH,
            GridBagConstraints.NONE, new Insets(5, 5, 5, 5), 0, 0));
 
setResizable(false);
setSize(600, 500);
setLocationRelativeTo(null);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
content.setBorder(BorderFactory.createLineBorder(Color.red));
        getContentPane().add(content, BorderLayout.PAGE_START);
 
setVisible(true);
 
  public static void main(String[] args) {
     theoryN StWin=new theoryN();  
     
}
}