Picture out more smaller circle with the color’s code #5D5F5E, placing it as in the next picture:

Blending Options>Drop Shadow:

Blending Options>Stroke:

Now we have to make one more layer on which we’ll put several spots, colored with #DADADA, as the next picture indicates it:

Press Alt button and make a mouse’s click between the spots’ layer and the circle’s one:

Set the rivets now:

Next we’ll just make a copy of the loud speaker and change the copy’s inside part with that loud speaker we’ve represented at the beginning. Place it on the upper music box, as on the next picture:

We have to represent another loud speaker. Make a copy of the metallic circle:

Represent one more circle inside the first one:

Blending Options>Gradient Overlay: