In many music videos, for example in T.I. feat. Lil Wayne - Wit Me music video from 1:14 - 1:17, u can see the video effect where the video switches from one scene to another very, very rapidly, syncing with that instrument/beat, what is this video effect called and how to put this video effect?
It's not an effect per se, it's plain old fast editing cuts. Some scenes have 1 frame, other 2 or 3 or more:
Just put two scenes on the timeline and go cutting from one to another, and aligning them with the sound waveform as you feel like. Beware that this should be used in really small doses of few seconds, otherwise it becomes an unpleasant stroboscopic effect.
In a nutshell: put one clip on top of another, and use transparency (or opacity) property to show / hide bottom video. For example, in Sony Vegas Pro you can use Composite Level envelope (there is also an extension to do it quickly). I am sure that other NLEs have similar tools.