Game Coding - No Enclosing Instance Of Type Background Is Accessible

So I'm fairly new to java and have been learning game development. I've come across this error message on my StartingClass.java coding. Here is the Coding

@Override
public void start() {
bg1 = new Background(0,0); // This line is giving me the error!!!!!!!!!!!
bg2 = new Background(2160, 0);
hb = new Heliboy(340, 360);
hb2 = new Heliboy(700, 360);
robot = new Robot();

Thread thread = new Thread(this);
thread.start();

The error reads "No enclosing instance of type BackGround is accessible. Must qualify the allocation with an enclosing instance of type BackGround (e.g. x.new A() where x is an instance of BackGround)." Now I have seven classes in my in my games src folder and none of them but the StartingClass.java has the error. Once again I'm fairly new to java and have not benn able to fix it.

These are the classes{

BackGround.java
Enemy.java
Heliboy.java
package-info.java
Projectile.java
Robot.java
StartingClass.java ( errors in this class )
}