9 against 4 quarter notes are 3 times faster of 3 against 4 quarter notes.

This triplets of a triplet concept makes double faced rhythm like the other relative of triplet, such as 3 against 2 quarter notes and 3 against 4 quarter notes.

3 against 2 quarter notes and 3 against 4 quarter notes require to divide 1 quarter note into only 3 for the explanation of their composition, though 9 against 4 quarter notes require to divide 1 quarter note into 9 for the explanation of its composition.

This number ₉ is the really revolutionary core.

In other words, 9 against 4 quarter notes certainly makes some sort of unique notes on its proceeding (Please check out the music and "Then, what? MIDI" above).

This condition of 9 against 4 quarter notes makes itself different from 3 against 2 quarter notes and 3 against 4 quarter notes.

The ₉ has both the ease like normal triplets and the odd feeling like "5" and "7."

The ₉ is a new way for subdivision of beat.

9 against 4 quarter notes can automatically create the notes less than 32nd notes, some pieces of 36 against 4 = 4 x 9-tuplet  ( As long as you play 9 against 4 quarter notes correctly ) .

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