Monday, April 16, 2012

Discussion and Thoughts on New Concepts

Meridian Arts Ensemble consists of brass instruments and a drum set.  A lot of their work is done in the style of rock and grunge.  The brass instruments have microphone in their bells and some of the pieces use effects pedals to distort the instruments.  This group commissions a lot of new works and I am particularly intrigued by this type of work.  

Gaudete Brass, performed a work by Ravel using brass instruments and theremin.  The concept is to take old ideas and adapt them for a new ensemble.  This inspired me to look into how the theremin works and I will post what I found from Wikipedia at the end of this post.  I never knew what the theremin was until my post tonal analysis class.  We listened to a performance done in the 1930’s of a theremin performing classical music, which is what this group is about. 

New Brass Directions is a large brass groups that plays nearly every genre of music.  Their goal is to continue changing the accessibility of brass music and bring it to a larger, more diverse audience.
TILT Brass Ensemble is a contemporary brass group who shares the common goal of exploring new genres and providing new music for brass ensemble.

There are many ways we can help to advance brass music and go in new directions.  Ideas of experimenting with new instrumentation, new genres and new composers are all great ideas.  Rather you are commissioning a work, composing one yourself or finding an old piece to adapt to a different group, all ideas help to further the cause.  I am a firm believer in bringing music to new audiences.  We need to strive to perform in less than common venues and draw diverse crowds.  I feel we owe it to ourselves and the public to not limit ourselves to playing recitals in concert halls. 

I was not a particular fan of the John Cage festival that was done at the UCC, but I am a fan of what was attempted to be accomplished.  It’s possible there were people there that have never heard a symphony band or a bassoon before in their lives.  Hopefully, it inspired someone to attend a recital or watch a youtube video they previously would not have.

The theremin is almost unique among musical instruments in that it is played without physical contact. The musician stands in front of the instrument and moves his or her hands in the proximity of two metal antennas. The distance from one antenna determines frequency (pitch), and the distance from the other controls amplitude (volume). Most frequently, the right hand controls the pitch and the left controls the volume, although some performers reverse this arrangement. Some low-cost theremins use a conventional, knob operated volume control and have only the pitch antenna. While commonly called antennas, they are not used for receiving or broadcasting radio frequency, but act as plates in a capacitor.

The theremin uses the heterodyne principle to generate an audio signal. The instrument's pitch circuitry includes two radio frequency oscillators. One oscillator operates at a fixed frequency. The frequency of the other oscillator is controlled by the performer's distance from the pitch control antenna. The performer's hand acts as the grounded plate (the performer's body being the connection to ground) of a variable capacitor in an L-C (inductance-capacitance) circuit, which is part of the oscillator and determines its frequency. (Although the capacitance between the performer and the instrument is on the order of picofarads or even hundreds of femtofarads, the circuit design gives a useful frequency shift.) The difference between the frequencies of the two oscillators at each moment allows the creation of a difference tone in the audio frequency range, resulting in audio signals that are amplified and sent to a loudspeaker.

To control volume, the performer's other hand acts as the grounded plate of another variable capacitor. In this case, the capacitor detunes another oscillator; that detuning is processed to change the attenuation in the amplifier circuit. The distance between the performer's hand and the volume control antenna determines the capacitance, which regulates the theremin's volume.
Modern circuit designs often simplify this circuit and avoid the complexity of two heterodyne oscillators by having a single pitch oscillator, akin to the original theremin's volume circuit. This approach is usually less stable and cannot generate the low frequencies that a heterodyne oscillator can. Better designs (e.g. Moog, Theremax) may use two pairs of heterodyne oscillators, for both pitch and volume.

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