September 2011

Good Vibrations: The Physics of Music
Book written by Barry Parker
Reviewed By Jeff Poth

  Ah, my loyal readers! What a pleasure to be writing for you again. As any of you who have read my other articles know, I try to make the write-ups for these pages very accessible. I'm not writing for engineers, who can track Audio Engineering Society (AES) papers and like lots of math, instead I'm writing for the moderate hobbyist who may have a technically proficient mind but is not a professional dork (no offense to professional dorks!). To that end, I picked up a book with a promising title for write-up in these pages while on a business trip in the city of brotherly love. That's right, Philly baby! 

Home of the cheesesteak notwithstanding, the title of this book as you may have surmised is Good Vibrations: The Physics of Music, referred to for the rest of the article as TPM. Authored by Barry Parker, this is a relatively lightweight look at the physics of music and sound. There is certainly some math and physics content, but mostly it bears similarity to my own writings in terms of difficulty and illustration. Why would a guy who is presumably fairly capable (that'd be me) be interested in such a text? I do it for you, dear readers! (Please tabulate my brownie points now.)

In truth, while the title and jacket were compelling as a target for a review in these pages, there's also always room for review and expansion. I spend lots of time deep in the classic red RCA tube bible and other such texts, but TPM fills a different need, containing quite a bit of review and visualization of the more fundamental premises.

There are quite a few images to support the text, which is a big plus when trying to understand the mechanism of a harpsichord, or periodic behavior for the uninitiated. The title of TPM can be somewhat misleading, as it's not a physics text, it merely uses light math and physics in explaining music and instruments and sound in fairly approachable terms. Sound too easy for you, oh great genius? I'd lay a nickel down that even most more advanced technical readers will have something to learn. Whether it be the reasons for the transition to soundboards in pianos, the underlying mathematics behind chords, or methods for visualizing pressure and transverse waves, there's something for just about everybody.

What to expect: A summary of the content as TPM is divided into four sections:

• Sound and Sound Waves
• The Building Blocks of Music
• Musical Instruments
• New Technologies and Acoustics

The first 50 pages or so are dedicated to "Sound and Sound Waves". This is where the text discusses the different types of waves, how they behave when encountering barriers (diffraction), and gets the reader familiar with the basics of sound propagation. Additionally, it discusses the hearing mechanism somewhat, a nice inclusion. "The Building Blocks of Music" completely diverges from this, discussing chords, the mathematical basis of tonal sound, harmonics, and the methods to our musical madness. More specifically, it delves into the basics of what makes a musical type sound the way it does- strong backbeats, rhythmic characteristics, and other components (including the scales used) of various musical genres. Examples of musicians for the various types are included, and a person with a solid record collection could have some fun listening to the various styles and getting a good feel for what exactly comprises them.

"Musical Instruments," to me, was the most compelling part of the reading. This section discusses the history of stringed instruments, including the piano and harpsichord. Diagrams and explanations of the physical nature, and operational mode of various instruments are provided, giving the reader a much better understanding of the nature of sound production, as opposed to the reproduction we focus on in hi-fi. (Up soapbox) The difference may seem minor, but while it's okay for a guitar speaker to be nonlinear and is just part of the sound, you don't want your home hi-fi playing everything so as to sound like a guitar. (soapbox away). The human voice is also discussed, with a nice diagram of the structures involved in speech/singing. There are examples of musicians who had particularly interesting styles (Paganini, Hendrix) peppered throughout the entire section, making for a much more interesting read.

"New Technologies and Acoustics" covers the rise of electronics in music, and how they're utilized and what they've meant to the industry. This is interesting material, and great for the music lover, but of more utility is the acoustics portion of the final chapter, where the role of the acoustic space of concert halls and recording studios is discussed. Home acoustics are one of the major shortcomings of most hi-fi setups, and the realities of how an acoustic space affects sound is rather sobering. To put it shortly- some acoustic foam at the first side reflection points is all well and good, but there are some pretty significant issues at play. TPM lightly touches on these, but naturally the serious analysis of an acoustic space requires more than is available in these pages. TPM gives a good visual representation of what the issues are, and defines the terminology, assuming the reader is a beginner. Again, more advanced scientific DIY'ers may find the reading somewhat lightweight, but the vast majority of readers will be encountering at least some new content.

Conclusion
If there's any question left, this text comes highly recommended to all but the most dedicated and well-read audiophile/ music lover. The first few chapters are great for those who could use help with the physical realities of sound transmission, and the middle portions of the book are tremendous for those looking for some historical and music theory content. Naturally, none of this is in-depth, any of the chapters in Good Vibrations: The Physics Of Music could be expanded to create an entire lengthy work, but for an introduction to these various facets of the nature of sound, instruments, and acoustics, Barry Parker does a superb job. I found the reading compelling and learned a few things, refreshed a few more, and enjoyed myself even in the sections where I was reviewing long-known bits.