How to carve a hollow cylinder along the curved surface in Fusion 360
If you want it to be engraved, then sketch out the sound wave on the center plane. When you go to extrude, click "extrude from", and then click "from object". Click on the plane you want to extrude from, and then 2xtrude however for you would like to. Another way to do this would be to project the sketch onto the surface, and then extrude the projection.