Tim O'Brien

Music 220A

Homework 1

ChucK files: Player_percussive.ck, Player_melodic.ck, and m220a-DataReader.ck

My data for this assignment is the annual mean temperature for three U.S. cities (New York, Santa Barbara, and Seattle) from 1895 to 2007. This data can be accessed here, and is provided by the National Climatic Data Center, National Oceanic and Atmospheric Administration. (The main data file I used is here, and I further extracted just the annual values for the individual cities by cross-referencing their corresponding USHCN station number, listed here. Finally I arrived at the below data files, which I used for sonification:

I then used the provided data reader file, m220a-DataReader.ck. I also used two main “player” files to sonify the data in interesting ways. The first is:

Player_percussive.ck

The sound here is produced with a noise generator running through a band pass filter. The frequency and Q values of this filter, along with the amplitude of the output signal, are dependent on the normalized value of the data.

In contrast to the example player file, this player achieves a more percussive sound because I do not use an envelop to change frequencies smoothly. The instant changes imply a beat with a strong attack. The noisy input signal also has a percussive effect, although at higher frequencies (i.e. higher data values) the BPF uses a smaller band and produces a more tonal sound reminiscent of a marimba.

The second player file I created is:

Player_melodic.ck

I use the BlitSquare oscillator here, and I have employed a reverb envelope to smoothly adjust the reverb amount as a function of the scaled data value, w. The particular function is plotted below. I think the additional reverb on lower data values (and notes) is interesting and compelling.

I created a sound file employing these two ChucK files, the three data sets, and two timescales (note durations of 90 and 180 ms). Please access it at: HW1_OBrien.wav