Music 171 homework 5

More practice with abstractions: this assignment is to build an additive synthesis instrument that can imitate the Hammond organ sound. Hammond organs have a set of eight "drawbars" that set the amplitudes of the first eight partials (harmonics) of the output tone. (There were lots of other features as well, but this is the one of interest here.) Your patch need not be polyphonic (it should be designed only to play one note at a time) but you should use the abstraction mechanism to make the eight overtones (each copy of the abstraction should make one of them). The overtones have frequencies of 1, 2, ..., 8 times the desired fundamental frequency of the note being played.

Part of the classic Hammond sound in rock music from the 60s and 70s was nonlinear distortion applied to the output of the organ (originally by overdriving the amplifier). In modern times this can be achieved using waveshaping, as was shown in class Feb. 8.

The novel Pd programming feature you will need to use is dollar sign ("$1", etc.) substitution in object boxes; this was introduced Feb. 1.

Your successful patch should sound like this.

To make the patch:

As before, make a zip archive of the main patch and the abstraction together in a directory as with last week's assignment. Remember not to make the patch make sound right when it loads (i.e., no loadbang into "pd dsp~" messages please.)

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