EQ (equalization) plugins are volume controls for specific parts of the frequency spectrum. Every DAW, mixing board and guitar amp has EQ controls, and they can radically transform your sounds. But while EQ is an essential part of audio engineering, it is also a source of confusion for beginners. In this post, I lay out some key vocabulary.
Category Archives: Science
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.
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.
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.
Groove: an aesthetic of measured time
As I work toward my future book on the theory of groove-based music, I’m reading up on the existing literature. There is not a whole lot of it! Most of the scholarly work about groove is about the social side rather than the music side. That’s why I was excited to find Mark Abel’s book, Groove: an Aesthetic of Measured Time. But then I was disappointed to discover that it’s a work of critical theory more than musicology, and I gave up on my first attempt to read it. Now I’m trying again.
Abel makes a book-length rebuttal of Theodor Adorno’s polemics against dance music. But Abel does not want to abandon Adorno’s Marxist critical framework; instead, he hopes to use that framework to come to a different conclusion about dance music than Adorno did.
What the heck is a decibel
If you are a musician or audio engineer, it is very important to know what decibels are. Unfortunately, decibels are extremely confusing. For one thing, there are so many different kinds of decibels! You only care about two of them: the decibels you see on a noise meter, and the decibels you see on a mixer. The decibel scale is meant to reflect the subjective experience of your hearing. A change of one decibel is a just noticeable difference: if you make something one decibel louder, that is just enough for the listener to notice that it’s louder. Makes sense, right? Unfortunately, decibels are logarithmic, which makes it hard to develop an intuition for the actual sound pressure levels that they represent. Let’s dig in.
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.
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.
The harmonic family tree
My blog stats have made it crystal clear that very few of you want to read about tuning systems. However, a vocal minority of you do love reading about them, and I definitely enjoy writing about them. So, let’s dig in and see how much Western harmony we can derive from the natural overtone series!
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:
The problem with just intonation – a visual guide
Tuning is the final frontier of my musical understanding. I start reading about it, and then I hit a big table of fractions or logarithms and my eyes immediately glaze over. However, tuning is important and interesting! So I continue to struggle on. Fortunately, as with so many music theory concepts, the right computer software can open up lots of new learning avenues. I have been having a great time with MTS-ESP by Oddsound. It was designed to help you hear and play different tuning systems, but it also visualizes them in an attractive circular way. If you read this blog, you know how much I love a good circular music visualization scheme.
So here is the basic problem with tuning. An ideal system (for Western people) would be based on the natural harmonic series, because we love how harmonics sound. This kind of tuning system is called just intonation. It sounds lovely! Unfortunately, just intonation makes it impossible to change keys orĀ tune your guitar. Let’s use MTS-ESP to figure out why that is. Continue reading