in the quiz for the harmony modulation lesson u say that applied dominants are necessary for Modulation. But in the Video when u modulate from Cmajor to e minor u only use the pivot chord a minor and the cadence B7 to e minor The applied Dominants u only use in the old key right? Why are they essantial for modulation? Thanks again for the help,its very cool u answer all the questions!!
To clarify, the dominant is required to confirm the key. If it is in fact a true modulation, you will need to confirm it with some kind of cadence, either Perfect Authentic Cadence (PAC), Imperfect Authentic Cadence (IAC), or Half-Cadence (HC).
I call it an applied dominant, but it is really just a matter of perspective. If you are still thinking in C major, it is an applied dominant (B7 is not a part of C) but if you are thinking in E minor, then it is just a dominant.