Moi Lolita - Alizee and Bach's prepared 9ths

Bach in his Niedt music manual refers to prepared 7ths, 9ths chords etc.


What does prepared mean?


These intervals are considered dissonant if heard or played abruptly. But if the brain is prepared for the interval to come they sound miraculously good.


Example of preparing is having the melody play an F sharp before bass E comes with F sharp to create the E 9th chord. For example Moi Lolita - Alizee written in B minor and produced by Mylène Farmer and Lautent Boutonnât.
Prepared 9ths come many times in this song. The best way to identify them is to play with the left hand (just on the left of the melody) the chords or bass and on the right hand the melody.
The bass derived chords are B, G, E, A in a loop. Of course every C and every F is sharp as the scale is B minor.
An obvious point is at 0:42. "Fou" is F sharp or FA#. "Qu'un" is F sharp too now with bass E to create the fabulous sounding 9th interval.
0:44 is great too as the end of the word phénomène is C sharp. There is sudden pause at the end of the word and the bass immediately goes B giving the great taste of 9th (B 9) as the C sharp reverberates in our conscience or perhaps by the vocal reverb.


Another example of prepared 9th is on Society's Child - Janis Ian. At 1:07 the organ plays a tremolo E which is sustained and then the bass becomes D creating with E and interval of 9th.  At 1:08 the organ E note is resolved to D.
https://m.youtube.com/watch?v=ABUmZvzGHVc



Another example of preparation is the melody descending by semitones or approaching from both sides the note to create the 9th interval. For example the music from Last Tango in Paris - Badbieri
https://m.youtube.com/watch?v=pq2kmegOWtE


The melody plays C, B, B flat, A with bass G and the 3rd from bass (B flat) added to make it sound superb.


The first technique can be seen in Mass in B minor - Bach.
The techniques can be studied by listening and watching carefully the score.
Examples are 0.14 one of the voices singing F sharp prepared and the bass E arriving. Or at 1:27.
https://m.youtube.com/watch?v=y-18Jup0m0U
Another great interpretation of this masterpiece is the one conducted by Karl Munchinger, Stutgart chamber orchestra.


References:


http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf


Mass in B minor - Bach - Dover publications


Harmony - Piston