What is the difference between analog and digital recording?

All microphones are analog. They convert pressure waves in the air into electricity. Pressure waves in the air vibrate a little piece of metal, and that generates a fluctuating electrical current. Different kinds of mics have different specific ways of doing this. In dynamic mics, the air vibrates a magnet. This magnet is wrapped in wire, and its motion produces a current in the wire. In condenser mics, the air vibrates a metal plate that’s part of a capacitor with an electrical current already flowing through it. As the plate moves, it blocks or admits more of the current, making the current fluctuate. There are other kinds of mics with other physical setups, but they all do the same thing: they send out an electrical current whose fluctuations match (are an analog for) the fluctuations of air pressure.

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Blues harmony primer

For a more detailed and scholarly version of this guide with a bibliography, see my Blues Tonality treatise.

How do chords and scales work in the blues? Is there a “blues scale”, and if so, what notes does it include? What are blue notes? Why does it sound good to play minor melody notes over major chords? To answer these questions, I combine my experiences of listening to and playing the music, talking to practitioners, and reading academic sources.

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Tuning is hard

I am committed to teaching my New School music theory students something about the history of tuning in Western European music. I don’t expect them to retain any details or do any math, I just want them to know that the history exists. In preparation, I continue to refine my explanation of this history to myself.

Before the year 1400 or so, Western Europeans mainly tuned their instruments in three-limit just intonation, which they called Pythagorean tuning. (Don’t be fooled by the name; this system was in use in Mesopotamia centuries before the Greeks described it.) Three-limit just intonation is based on the first three harmonics of a vibrating string. Western Europeans really like the pitch ratios produced by these harmonics, as do people from many other cultures (though not all of them). In this post, I will explain why Europeans liked three-limit just intonation, why they nevertheless eventually abandoned it, and what came after.

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Aural Skills for Audio Engineers

Montclair State University asked me to develop and possibly teach a class on aural skills for audio engineers. It’s a great idea! It isn’t just audio engineers who need to know what frequencies and decibels are. These are concepts that any musician would benefit from knowing.

The internal ear

Here’s my first pass at a course outline. The main problem is that this is five semesters worth of material, so I’m sure some of it (a lot of it) will get cut. But these are the things I would want to cover in an ideal world.

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Seventh chords in just intonation vs 12-TET

I enjoy listening to Jacob Collier explain his music more than I enjoy the music itself. His arrangement of “Moon River” is mostly exhausting. However, Miles Comiskey pointed me to an interesting moment in this explainer video at the 1:04:22 mark where Jacob talks about how Kontakt enables you to change your instrument tuning on the fly.

Jacob takes a dominant seventh chord and plays it in two different tuning systems: twelve-tone equal temperament, the system we’re all used to, and just intonation, which is a more “pure” harmonics-based system. The chord sounds very different in the two systems. That is a profound musical concept that is not easy to understand! Jacob buries it in his song under five thousand other ideas, but I thought it would be helpful if I built a whole track around it:

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The blues and the harmonic series

In this post, I’m going to expand on an idea in my blues tonality treatise: that the distinctive scales and chords of the blues are an approximation of African-descended tuning systems based on the natural overtone series. Gerhard Kubik argues in his book Africa and the Blues that blues tonality comes from the overtone series of I and IV, and can only be approximated using instruments tuned to standard twelve-tone equal temperament (12-TET). Let’s unpack what that means!

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Why can’t you tune your guitar?

Short answer: because math. Longer answer: because prime numbers don’t divide into each other evenly.

To understand what follows, you need to know some facts about the physics of vibrating strings:

  • When you pluck a guitar string, it vibrates to and fro. You can tell how fast the string is vibrating by listening to the pitch it produces.
  • Shorter strings vibrate faster and make higher pitches. Longer strings vibrate slower and make lower pitches.
  • The scientific term for the rate of the string’s vibration is its frequency. You measure frequency in hertz (Hz), a unit that just means “vibrations per second.” The standard tuning pitch, 440 Hz, is the pitch you hear when an object (like a tuning fork or guitar string) vibrates to and fro 440 times per second.
  • Strings can vibrate in many different ways at once. In addition to the entire length of the string bending back and forth, the string can also vibrate in halves, in thirds, in quarters, and so on. These vibrations of string subsections are called harmonics (or overtones, or partials, they all mean the same thing.) Continue reading

Four bars of Mozart explains everything humans like in music

I’m not arguing here that everyone loves Mozart, or that I’m about to explain what all humans enjoy all the time. But I can say with confidence that this little bit of Mozart goes a long way toward explaining what most humans enjoy most of the time. The four bars I’m talking about are these, from “Eine Kleine Nachtmusik.”

These four bars of music demonstrate that humans like:

  1. Repetition
  2. Breaks in the repetition
  3. Repetition of the breaks in the repetition
  4. Breaks in the repetition of the breaks in the repetition
  5. Recursive layers of patterns of breaks and repetitions

In order to prove this to you, I’m going to talk you through these eighteen notes one at a time.

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The vocoder and Auto-Tune

The vocoder is one of those mysterious technologies that’s far more widely used than understood. Here I explain what it is, how it works, and why you should care.

Casual music listeners know the vocoder best as a way to make the robot voice effect that Daft Punk uses all the time.

Here’s Huston Singletary demonstrating the vocoder in Ableton Live.

You may be surprised to learn that you use a vocoder every time you talk on your cell phone. Also, the vocoder gave rise to Auto-Tune, which, love it or hate it, is the defining sound of contemporary popular music. Let’s dive in!

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