TEC154 2010S, Class 16: Instruments

Overview:

Admin:
* There will be two short readings for Wednesday which will be distributed via email.  Make sure to respond to those readings.
* I apologize for being behind in transcribing notes.
* These notes are as recorded by Sam Rebelsky.
* Upcoming performance of instrument from Gambia

Preliminaries
* Prof. Vetter read through your questions, but won't be able to respond to them all (particularly since he's not a physicist).  Feel free to ask questions during the presentation.
* He's happy to demo, but won't be able to tell you a lot about how the transfer of energy to various materials makes sound.
* Focus: continual feedback between music makers, audiences, and instrument makers have changed instruments

Slide: Model of the Genesis and Evolution of Musical Instruments
* At the center is a musical instrument
* We see overlapping domains of the music maker and the musician
* Makers produce the instrument, using "tools and transformational
  know-how applied to design and construction", knowledge of acoustical 
  principles, knowledge of visual symbolishm, and available raw materials.
* Four compoents
  * Design and construction; redesign over time
  * Material product (instrument)
  * Application (performance)
  * Sonic product

Narrative:
* Many devices for making sound, many of which convey information even
  if not musical.  (E.g., the tornado siren, a fire engine's siren.)
  These are still "instruments"
* A musical instrument is any material object that is used to produce
  sound that is considered by members of the culture as "music".
  * An instrument that is foreign to your culture may not sound musical to you.
* The domains of maker and musician overlap at the instrument.  
  * It's in the makers' domain in that they use skills and knowledge to 
    produce the instrument.  
  * It's in the musician's domain in that they use their sensibilities,
    imagination, and skills to create sound (which is then performed).
    * "Touch" is at the center of the musician's interaction with the
      instrument
* Musicians' performances create a feedback loop with the audience
  ("We can't hear X" or "I want to convey X better")
* Musicians' ideas and judgements create a feedback loop that informs
  the maker
* Makers of instruments have an understanding, if only an intuitive
  understanding, of techniques for making sound
  * We know that different instruments can make the same note
  * But we can also distinguish the two sounds (e.g., a piano vs.
    a trombone)
  * Sound is a multifaceted phenomenon
  * We hear frequency (the pitch)
    * Perhaps absolute
    * More frequently relative (e.g., one is "higher" than the other)
  * We hear intensity (the volume, from soft to loud)
  * We hear overtone structures
    * The ability of most things to vibrate in multiple modes at
      a time.
* ENERGY IS SO MUCH OF UNDERSTANDING MUSICAL SOUNDS
  * Sound is energy
* Demo: A plucked string instrument
  * Stretching the string inserts energy
  * The string vibrates to release the energy
  * The string has multiple modes of vibration
    * The main vibration
    * Selected in middle eliminates main vibration, so we hear the
      first harmonic.
  * Although most of us can't explain the physics, people around the
    world have discovered this
  * Note: Energy can come from multiple sources (example of piano
    in which we have one string vibrate because energy was imparted
    from other strings)
* Demo: Aerophones
  * Plays single note on trumpet
    * We hear resonation of many of the other instruments in the room
    * Illustration of overtones
    * Illustration of imparting of energy to other instruments
  * You can get multiple sounds from the same length of tubing
    * By changing the frequency of your "buzzing" you can get different
      modes (frequencies) of vibration.  
    * You don't hear the buzzing of lips, you hear the frequences
      of the air vibrating.
* Again, even if we don't understand the physics, we can "know" some
  of the acoustic principles
* Makers must have a toolchest that permits them to transform the
  materials that they or their ancestors have found 
  * How thin to shave a wooden soundboard 
  * How thick to make the brass in a trumpet
* Often, the tools and technologies of transformation come from other areas
* The materials around us affect what we decide to use for instruments
* Example: Drums
  * We'll never know how drums were discovered
  * But we can envision natural ways in which they could be ... E.g.,
    we stretch hides during drying, and it's easy to envision wind
    making it vibrate or someone hitting it by mistake or ...
* New materials get developed, and can sometimes be substituted
  * Example from Gambia - Stretched animal hide was the original string.
    Then fishing line came into the area, and some makers started
    substituting it.  
* Note: Instruments can become associated with particular groups.
  * There are also other characteristics of the instrument (e.g.,
    symbols we place on them) that have significance.
  * Communicate meaning other than visual sounds.
* Social and cultural actors have a big role.

Questions
* Explain timbre
  * Different sounds from different instruments
* Is there evidence that older instruments sound better (at least for
  stringed instruments)?
  * Probably a lot of cultural issues mixed in there
* Is there a geneaology of instruments?
  * An interesting question
  * No, there doesn't seem to be
  * There isn't enough evidence 
  * But for newer instruments we can see this
* Open-ended vs. closed ended
  * Open-ended overblows at an octave
  * Closed-ended overblows at an octave and a fifth