A keyhole saw or a sabre saw will do that.
Sabre saws are good for cutting curves and small holes in wood .
For cutting round holes.
The ribs on the violin is the curves on the side of the violin, by the f holes.
Tenon Saw : Used to cut metal tubes, rods and metal sheets. Hacksaw: Used for cutting straight lines in wood. Crosscut Saw: Used to cut wood purposly at 90 digrees to the wood grain. Coping Saw: Used for cutting a range of woods. Usefull for cutting shapes and curves. Keyhole Saw: Used for cutting small holes in wood.
For cutting round holes.
Boring holes and pouring acid into them.
Nobody else has tried to answer your question, so let me say this: I think you can do it by enlarging the 4 center holes to allow for the slightly different angle. More research would be in order before cutting good parts.
For cutting irregular shapes in wood. One practical and common use is cutting holes for sinks in wood/laminate countertops.
You use it for cutting small irregular holes in wood
CNC cutting has a very wide range of applications, like cutting metals and plastics, but also sawing, drilling holes, gluing, welding, fiber placement and bending.
A jigsaw is used for cutting curved or round holes. With a straight guide it can cut straight lines.
A 1996 Ford F-150 uses 9" size speakers standard. Owners can upgrade to larger speakers by using a speaker box or by enlarging the holes.