To make the patch (each of the following steps is worth 2 points for a total
- Download this flute recording. Load it into
an array in your patch. (You can use the soundfiler object to load it; be sure
to use the "-resize" flag to get the array resized to the size of the soundfile.
Make the array save its contents using the properties dialog, so that you don't
have to make the patch automatically load it each time. (This flag can reset itself
spontaneously so make sure it's activated.)
- Using phasor~ and the technique shown in class Thursday (adding 0.5 and
using the wrap~ object), make two phasors that are one half cycle out of phase,
to read into the downloaded array. Use the windowing technique (also shown in
class) to control the amplitude of each one of the two tabread4~ outputs so that
they are zero at each moment the phase wraps around from 1 to 0, to avoid
hearing a 'click' sound.
- Make another array, with 12 elements. Its y-value range should be set
from 2 (for example) to 0 as you descend from its top to bottom.
This table should control the frequency of the phasor~ object described above, so that you
hear a sequence of 12 different speeds of playback (which will sound like 12
different musical pitches.) You will have to use another phasor~ object to read
the values in sequence, and a tabread~ object (no interpolation!) to read the 12
values. This is the same operation as reading the flute array except that the
table only has 12 values instead of the many thousands that the flute array will
have. When you have this working you should hear a sequence of 12 audible
transpositions of the flute sound.
- Find reasonable frequency for the controlling phasor~ object, and
reasonable values to put in the 12-element array (which controls the pitches),
and a reasonable range of values over which to read the array holding the
recorded flute sound. Once this is working you should hear a sequence of 12
pitches that repeats forever.
- Once you hear the sequence of pitches, you can then duplicate the entire
patch, this time using a slightly different frequency (only 0.1 or even 0.01
different) to get the effect in the example. Make sure that the patch you make makes
sound as soon as you open it and start DSP.
Note: the included flute recording was downloaded from freesound.org.
It's on a Creative Commons
license (attribution; non-commercial), uploaded by Carlos_Vaquero.
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