Does anyone have any tips on how to do pseudo modulation (fake modulation)?
Those two videos and the song "moon river" is the most i seen on it.
Does anybody have any more constructive tips on how to do it?
The underlying theory is that any key you start from is a modal key in every other key. When you start playing, the choice of notes leads the audience's ear towards a particular key, not necessarily consciously, and that key has psychological implications which keys the audience to particular emotional palettes. However, because the chords do not fill the scale, each interval used actually filled only slightly reduces that choice - this is why dodecacophony is so psychologically distressing to someone lacking the auditory education to handle it. Particular intervals - notably the seventh, the "leading note", but also the blues diminished sixth and some others - leave the ear seeking resolution, not necessarily in the key you're actually in. The tease can be the use of a passing note to hint at an intention which never comes to fruition.
What's actually happening is that the hint takes the audience into the other key, but the modulation is a two-way street and no sooner does the performer put his nose round the corner than he realises it's not where he intended to go and comes back again, leaving the audience rushing to catch up having seen a world they're not being taken into.
In the video, the instructor speaks of such a fake modulation "written into Rainy Day." Do you have the score? Take a look at pieces of music that do what you want and analyze. See what they do.
It looks like we're mostly looking at chromatic thirds ("going to" Ab major in F major), but instead of staying there, do another one to get back to the original. For instance, in F, tonicize Ab, then do another chromatic third to C7 which goes back to F naturally. It will "feel" like you've gone a long way, but of course, you're back where you started.
Another example (from the video which you posted) is (in F again) tonicize Ab, and even play V/Ab (Eb7), then simply continue in F. It's not as jarring as it ... sounds.
Unfortunately, I can't watch the video right now, but I do know the main melody of Moon River. So, looking up pseudo-modulation and a lead sheet, I believe I see what you're referring to. For the most part, this pseudo-modulation is taking advantage of the circle of fifths and ii-V-I cadences to lead the ear temporarily astray for intrigue. It starts off in C major and is simple enough. Then we get our first iio-V-i, the minor equivalent of ii-V-I, right before the first ending. Bm7♭5-E7-Am7 brings us to A minor, just the relative minor. Again, nothing crazy.
Then, at the beginning of the first ending, we have an odd C7 chord. The C is usually just a major or major 7 chord in A minor, but the dominant seventh and the Fmaj7 chord right after it make it function as a dominant chord. So C7-Fmaj7 and now we're in F major. But that only lasts for one chord, as the Bb, which is normally the 4th of F major, is also a dominant chord is leading a halfstep down right back into A minor with the Am7. The Bb7 was acting as a tritone substitution.
We don't stay in A minor for long, though. The next three chords are a iio-V-i, except the V chord is substituted with its tritone partner, F7. So the F♯m7♭5 acts as the iio chord, the F7 acts as the v chord, and Em is the new tonic. Except, oops, your ear was wrong because now that Em7 is acting as the ii chord for the next cadence. Em7 is the ii, A7 is the V, and Dm7 is the i. And again, your ear has been deceived, as the Dm7 was actually the ii chord for a ii-V-I right back into C where we started.
Then, everything is normal or repeats old concepts until we get to the last few chords, starting with C♭. Honestly, without being able to hear the song, I'm not sure what's going on here. It looks like just a bunch of chromatic motion downwards back to Cmaj7. Regardless, it's quite amazing because although all of these quick cadences should be leading into other keys, they're really just dancing around C major and A minor. Most of the chords are just slight alterations of chords from our main keys and our ear is just led by the chain of fourths. This is rather common in jazz and has a wonderful effect. I'd never heard it referring to as pseudo-modulation before, though. Makes sense.