Using the Hénon attractor
In order for this example to work correctly, you first need to download the patch called henon.maxpat and place it in the Max file search path.
In order for this example to work correctly, you first need to download the patch called henon.maxpat and place it in the Max file search path.
I believe that we respond to and recognize something about the shape of the change in a sound, and that shape forms a metaphorical sonic "gesture" in our minds. The "shape of the change" means the way in which some aspect of the sound (it could be any measurable parameter) or the music (it could be any characteristic we care about) changes over time: how radically it changes, and with what acceleration of change. That can be simply stated as the value of the parameter in question, depicted as a function of time. That is, the "gesture" can be depicted as a curve of change over time.
The cycle~ object uses a lookup table of 512 values that make the shape of a single cycle of a cosine wave, and it reads through those repeatedly at whatever rate is specified in its left (frequency) inlet. You can also set the cycle~ to 0 Hz (its default frequency) and select a point in the cosine waveform with a value (either a signal or a float) from 0 to 1 in the right (phase offset) inlet.
This is an algorithmic generator of sound patterns based on the number 6. The patch a) uses the urn object to generate a list consisting of a random ordering of the six digits 0 to 5, b) uses a metro to bang a counter six times per second in order to count through that list of digits, c) uses those six digits to produce six frequencies representing harmonics 7 through 12 of a fundamental (110 Hz, initially), and d)uses those freque
This example demonstrates how the settings of a resonant bandpass filter can be altered in a rhythmic way for musical effect. The three table objects each contain 16 numbers, which will be used as the parameter settings for gain, center frequency, and Q in a reson~ object. The numbers in the table objects are looked up by a counter that cycles repeatedly through the table indices, 0 to 15.
The reson~ object is a resonant bandpass filter; it passes frequencies in a specified region, and attenuates the other frequencies. It requires only three parameter values: input gain, center (resonated) frequency, and a resonance quality factor (Q). The Q determines the bandwidth of the passed region around the center frequency. Specifically, Q is defined as center frequency divided by bandwidth, where bandwidth is the extent, in Hertz, above and below the center frequency before the frequencies will be significantly attenuated.
This example demonstrates one of MSP's many filter objects—the resonant bandpass filter reson~—and demonstrates how a parameter of that filter—in this case its center frequency—can be easily modulated by a low-frequency control oscillator (cycle~). The range of cycle~ is between 1 and -1, but that range can be amplified by multiplication, and can be offset by addition.