This Week’s Program: Feb 22 - Feb 26

Even though we celebrated President’s Day last week, George Washington was born on February 22nd. And that is why I’ve dedicated the subject line to him.

It was a week that started slow and picked up momentum along the way.

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I bring in another one of Overtone’s built-in synths, the “overpad”, which has a cool synthy sound.

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Using the primitives I built last week, this is my initial sketch for composing a “song” based on a bpm and a scale. The channel returned by the overpad is conjoined to the drummachine channels.

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I essentially replicate the above make-song function in the main fn. Here’s what that sounded like: RNG Seed 1456347630950

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At this point, I wanted to abstract song creation and generation from the main function. The main function should be responsible for just the imperative linear parts of this, and the song generation should be encapsulated somewhere else.

This patch did several things:

• In the above SoundCloud clip, you hear a hard cut-off when the song ends. I adjusted the play-sequence fn to wait one additional metronome tick before writing its completion bit.
• I expanded the function signature of make-song to accept more variety in composition.
• I created a function to replay a song from a previous seed.

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Now the problem with the above was that I had that binding to the RNG seed every which way, and was duplicating lots of functionality. I consolidated all of that in this patch. gen-song takes a seed and constructs a song from top to bottom. Pass in the same seed, you get the same song! This combines the make-song and replay-song fns and abstracts away all of the previous concerns of the main fn.

In addition, I put the Lein project version onto the S3 object’s metadata. A song is a function of its RNG Seed and the version of the code that produced it.

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I bring back the 303 and have the RNG control its parameters.

The result: 🎵 Andante C4

I can then use the same seed, but change the internal parameters eg. I can choose a faster tempo and a different musical scale. The result is similar in structure: 🎵 Allegro D3 Minor

Next week, I’ll be exploring more of the functionality of core.async to better handle song control flow and will be tweaking the parameters of song generation.

I would love to hear your feedback this week.

– Mark