Well in this tutorial and the main focusing is one the ball and light. The rest can be design to be look more nicer amoung the ball. It is actually quite simple, the technique is to create the texture first and map it onto the 3D sphere. However, we will require Illustrator CS and above to create this awesome Illustrator effect.
1. Create the Disco Ball
Select the Rectangle Tool (M) and make a square object with light blue color. After this select the square object and hold Alt key then drag to make other object and give it as black color.
Try to duplicate the above object until you get this and make sure you give different color like in a club because will are trying to make a disco ball. Then make another object by copy again. See below image
Once every object is done. Drag to the Symbols tab and leave it one side.
2. Create a 3D sphere
Well let's get your tool ready. Press (L) for making a cycle object and press (M) to draw vertical object as seen. Join it together but just haft of each. Then press Ctrl + Shift + F9 for a Pathfinder option. Make sure you select both object and press Subtract Sharp Area in the Pathfinder dialogue then finally you get a result in below image.
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Let make this object into 3D. Select it and go to Effect menu ==> 3D ==> Revolve then 3D dialogue is appeared.
Press Map Art and one the symbol type select an object which we had drag to symbol (just remember that: your 3D object must smaller then symbol). Try to find the face of it in surface.
and now you get the ball. Give background in black and start making a light star.
to make a star light you can use what ever tool to make it and give some effect. Now let's use Pen tool and pen it as a star. Make a cycle object and gradient as type Radial black and white and on the same object go to transparency tab to make layer mask and make it as shadow. And make it into one object. See below
Try to past it in some part of the ball. And last one do same thing but make only lighting without star in the middle of ball.
Here is the finall result.