This example is from my Algorithmic Composition blog, and is explained there.
This patch uses the table object to calculate a probablility distribution to make the short notes occur much more often than the long notes.
Each MSP object (each object that has signal input and/or output) is always producing signal as long as audio is turned on. For example, signal generators like cycle~ (sinusoidal wave generator) and saw~ (band-limited sawtooth wave generator) are always producing a full-amplitude wave. You control the amplitude of that wave with multiplication, using *~ or some other object that performs a multiplication internally (such as gain~).
An exponential amplitude fade is usually more subjectively natural-sounding than a linear amplitude fade. This patch allows you to compare the two.
Whenever the time interval of a metro object is specified using tempo-relative time units such as note values, the operation of that metro will be governed by the transport.
This example repeatedly arpgeggiates the first 16 notes of the harmonic series based on the frequency 65.406395 Hz, which is the fundamental frequency of the open C string on a cello. The note rate can be adjusted anywhere from 1 note per second to 100 notes per second. The default initial rate is 8 notes per second.
This example shows how, instead of switching instantaneously from one audio signal to another, we can do a quick crossfade between signals, thus avoiding clicks. The patch illustrates a common reason for switching signals––to bypass an audio effect.
Whenever you change the delay time, you're asking MSP to look at a new location in the delay buffer, which can cause a click in the output if the new sample value is very different from the previous one. One way to get around that is to quickly fade the output amplitude down to 0 whenever you make a change, then quickly fade it back up once the change has been made.
The fact that groove~ can leap to any point in the buffer~ makes it a suitable object for certain kinds of algorithmic fragmented sound playback. In this example it periodically plays a small chunk of sound chosen at random (and with a randomly chosen rate of playback).
The play~ object can be controlled by any MSP signal in its inlet. The value of the signal controls the location in the buffer~, in milliseconds. Normal playback can be achieved in this way by using a linear signal, such as from a line~ object, that traverses a given time span in the expected amount of time.
The line~ object generates a signal that interpolates linearly from its current value to a new destination value in a specified amount of time. It receives messages specifying a new value and the amount of time (in milliseconds) in which to get there.