Prepared Piano

[ian-s]

At the risk of flogging a dead horse, here is another Piano patch. This one is perhaps more in line with what members here would like. Variation 2 is a 'prepared G2 Piano'. As absurd as that is, the techniques used may be of interest to others.
The most obvious module to use would probably be the note detector but I have used constant compares in combination with some logic gates to give me controllable zones, each with it's own output to perform the mangling.
For those who don't know, prepared piano involves stuffing junk (paper, tacks etc) inside the piano to modify the sound. This technique probably reached its peak with the popular avant-garde 80's duo 'Stockhousen and Waterman'.

Logic Mini Tutorial
For those interested, this patch shows one use for the logic gate module. The keyboard module 'note' output produces 0 for E4 key in the middle of the keyboard, and increases/decreases by one for each semitone up/down (D#4 is -1, F4 is 1).
I have connected this control signal to the input of 4 constant compare modules. The output of each of these modules will go high (0->64) when the key number input is greater or equal to the knob value.
I am using the XOR gate function, this is short for eXclusive OR. The output will go high only when one or other (but not both) of the inputs is high. This means that each gate output goes high only when the key falls between the ranges of the constant compares.
In this patch, the third gate signal needed an inverter to produce the effect I wanted, instead of using an inverter module, I simply used the NXOR (NOT XOR) gate option. The 'N' in front means the output is inverted or the opposite of the XOR.
This arrangement is called a window switch* and would work with other types of input. A very slow LFO for timeline stuff (replace the constant compare with a CMP B driven by a 'course + fine' mixer for 1/16384th timing control).

*The switch group has a window switch module but it would require level conversion to use with the keyboard note signal, and does not have the ability to use 'fine' control.

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prepPiano.pch2
Description:	prepared piano (variation 2)	Download (listen)
Filename:	prepPiano.pch2
Filesize:	3.22 KB
Downloaded:	2353 Time(s)

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