Dr. AIX's POSTS — 15 July 2014


It’s summertime and the living is easy. Life is good. Running the new puppy at the beach early in the morning or trying to wear him out at the end of the day with a few dozen tosses of the Frisbee at the park has become a daily ritual for Charlie and me. Having a break from the university responsibilities and classroom time with students is one of the benefits of being a professor. I’m not sure how other educators occupy themselves during their summer break, but I refocus on my studio work and writing.

But today I’m preparing to leave town for 24 hours and spend a few hours educating a group of 40 or so corporate music people about music, audio recording, high-fidelity and production. What takes two semesters at the university and countless lab hours in the studio needs to happen in a couple of hours. Well, at least the basic concepts need to be presented and some reasonable demonstrations experienced. I’ve been asked to avoid the technical stuff and focus on the overall concepts. Here are some of the questions and answers that will be included in the Dr. AIX two-hour condensed course on music, audio and high fidelity.

Q – What are the basic components of music and what do they contribute to the art of music?
A – Melody, Harmony and Rhythm. Melody is a linear collection of pitches distributed through time according to a specific rhythm. Harmony is a vertical collection of simultaneously sounding pitches typically used to accompany or support a melody. Rhythm is a series of proportional durations associated with sounding pitches.

Q – What is a pitch or note?
A – An individual musical tone.

Q – What is the relationship between the basic parameters of music and the science of acoustics?
A – Pitches are the discrete frequencies. While frequencies extend continuously from DC [direct current] to infinity, pitches are limited to 12 discrete audible frequencies named with 7 letters of the alphabet with sharps and/or flats. The chromatic scale is all of the pitches or notes available to composers and songwriters in traditional western music [c, c#, d, d#, e, f, f#, g, g#, a, a#, b].

Musical timbre or the “color of sound” is what allows us to distinguish between a middle “c” played on a cello and a middle “c” played on a trumpet. Timbre is referred to as the harmonic spectrum and can be measured examining the frequency components and their amplitudes from the lowest fundamental frequency to the highest harmonic.

Musical Dynamics are the difference loudness levels that an individual instrument or ensemble can produce. Dynamic markings in music are relative to each other and range from pianississimo (ppp) to fortississimo (fff) and everything in between. Musical dynamics equate to amplitude in acoustics and are measured relatively using dB (decibels).

Q – How does audio recording attempt to “record” the elements of music?
A – Audio engineers use transducers called microphones to convert the acoustic energy created by performers into analog electrical signals that “mirror” the characteristics of the music in terms of frequency (pitch), harmonic spectrum (timbre) and amplitude (dynamics). They do this with equipment that can store the information for a period of time and then reproduce it later.

Q – What formats are used to record and reproduce audio?
A – Throughout the roughly 150 years of audio recording, engineers have used physical means like cylinders and platters to store an “analog” of the musical information, linear rolls of magnetic tape, spinning optical disc sampled with “digital” pits capable of recreating the original musical information and streams of digital words pulled from solid state storage or through wired and wireless networks.

Q – What tools and recording formats have been used to make recordings?
A – Throughout the evolution of recording techniques and equipment, engineers have used acoustic horns to concentrate music and etch it onto a spinning lacquer disc, electronic microphones to generate analog signals that could be recorded directly to disc using sophisticated amplified cutting lathes, capture the analog signals using magnetic tape in mono or stereo or over many individual tracks (multitracking) or as ones and zeros using complex digital converters and computer storage.

Microphones, mixing consoles, recording machines, signal processors and monitoring systems all contribute to a successful recording. But each engineer brings his or her own unique recording methodology to each production.

To be continued…

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About Author


Mark Waldrep, aka Dr. AIX, has been producing and engineering music for over 40 years. He learned electronics as a teenager from his HAM radio father while learning to play the guitar. Mark received the first doctorate in music composition from UCLA in 1986 for a "binaural" electronic music composition. Other advanced degrees include an MS in computer science, an MFA/MA in music, BM in music and a BA in art. As an engineer and producer, Mark has worked on projects for the Rolling Stones, 311, Tool, KISS, Blink 182, Blues Traveler, Britney Spears, the San Francisco Symphony, The Dover Quartet, Willie Nelson, Paul Williams, The Allman Brothers, Bad Company and many more. Dr. Waldrep has been an innovator when it comes to multimedia and music. He created the first enhanced CDs in the 90s, the first DVD-Videos released in the U.S., the first web-connected DVD, the first DVD-Audio title, the first music Blu-ray disc and the first 3D Music Album. Additionally, he launched the first High Definition Music Download site in 2007 called iTrax.com. A frequency speaker at audio events, author of numerous articles, Dr. Waldrep is currently writing a book on the production and reproduction of high-end music called, "High-End Audio: A Practical Guide to Production and Playback". The book should be completed in the fall of 2013.

(6) Readers Comments

  1. Those music execs won’t absorb 10% of this info. What they need to know is that the public as a whole has figured out that MP-3 sucks, hi-res is now with us, data storage is cheap, not like I-pod days, and that the music business and the public, mass enjoyment of music has entered a new era. Don’t sell folks short; they WILL hear the difference between only 5% of their music’s content actually audibly manifesting compared to the freight train of music that is 24/96 master tape download. Good sound for the masses will do society much more good than great sound for the few. This is why hair-splitting and divisiveness has no place in this movement. Whether or it’s Pono, or AIX, or Chesky, who cares about provenance as long as it sounds demonstrably excellent and has the audio qualities associated with master tapes that are rarely found to any great degree on any CD. Critical insights are only really important if they help produce positive benefits on a large scale.

    • Craig, this is not about “hair-splitting and divisiveness”, but about providing accurate and meaningful information to potential customers.

  2. The discussion of pitch seems to be confusing the concepts of pitch and pitch class. In traditional western music there are only 12 pitch classes, but each of these pitch classes is composed of many different pitches. The difference between a C0 and a C10 pitch is part of what is being captured in a high resolution recording.

    • I thought it better to leave pitch class out of the discussion…my point was to distinguish between pitch and frequency.

  3. Mark, why don’t you video record it and then offer it for sale?

    • I’ve thinking a lot about creating a series of educational videos…it’s a bunch of work and I already have plenty of that.

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