When you think you're getting somewhere

When brainstorming, ideas can come slowly, other times its a constant flow. For the credit scene, which will be the first 30 seconds or so of our film opening, computers, smart phones, and other types of technology will appear on a black surface while a long take will show the different credit names. As the camera sways from computer to phone, the surface changes colors and the credits starts appearing on items that are not related to technology at all, such as paper, pencils, ect. So, in my head I can clearly picture the twists and turns of the 30 second reel; however, last night I realized something important that I missed. How does someone pick the right music? Can someone explain this to me? To have the right music is so important, it sets the tone for the rest of the movie so I cant exactly just pick something random. I guess its time for some research.

                                                                           xoxo Laerke