Tutorials and Topics - Peabody Computer Music

Tutorial 7Synthesis:Additive synthesissource, their relative frequencies will stay the same even when the value of thefundamental frequency changes.Of course, for the sound to be very interesting, the amplitudes of the partials must evolvewith relative independence. Therefore, in the main patch, we control the amplitude ofeach partial with its own envelope generator.Envelope generator: functionIn Tutorial 3 you saw how to create an amplitude envelope by sending a list of pairs ofnumbers to a line~ object, thus giving it a succession of target values and transition times.This idea of creating a control function from a series of line segments is useful in manycontexts—generating amplitude envelopes happens to be one particularly commonusage—and it is demonstrated in Tutorial 6, as well.The function object is a great help in generating such line segment functions, because itallows you to draw in the shape that you want, as well as define the function’s domain andrange (the numerical value of its dimensions on the x and y axes). You can draw afunction simply by clicking with the mouse where you want each breakpoint to appear.When function receives a bang, it sends a list of value-time pairs out its 2nd outlet. That list,when used as input to the line~ object, produces a changing signal that corresponds to theshape drawn.function is a graphic function generator for a control signal when used with line~By the way, function is also useful for non-signal purposes in Max. It can be used as aninterpolating lookup table. When it receives a number in its inlet, it considers thatnumber to be an x value and it looks up the corresponding y value in the drawn function(interpolating between breakpoints as necessary) and sends it out the left outlet.100