As part of her undergraduate Music studies, 3rd year undergraduate Lucy Currid is working on a project which uses the resonant frequency of a building to both generate harmonic frequencies and create the basis of new musical pieces.
As a member of Inter Alios, the joint choir of Churchill and Murray Edwards Colleges, Lucy is accustomed to the Chapel at Churchill College as a performance space. The Chapel is built in the shape of a Greek cross, built of concrete beams with a timber roof, offering significant differences to traditional Chapel acoustics which Lucy sought to explore.
Lucy was interested in writing a piece that incorporated different instruments trying to ‘sound’ a room and build a picture of the room from their sonic interactions, similar to echolocation with animals. Lucy said, “I had envisaged the piece being performed in the Chapel at Churchill, a space I am familiar with and really enjoy being in, and so came the idea to discover what this room really did ‘sound’ like! I am keen to compose pieces of music with multiple access points for listening, incorporating non-‘musical’ creative material to produce an interesting sonic experience for the listener. As such, exploring and utilising the sonic properties of the Chapel was an intriguing path to follow.”
Through the process of establishing the resonant frequency of the building, the room itself starts to generate sonic feedback and tones which Lucy will be using to create music which ultimately will be performed in the space. To go about finding the frequency, Lucy worked with the Director of Music, Dr Ewan Campbell, and the College’s Audio-Visual team. Setting up four speakers, with each one faced towards an outer wall, frequencies were broadcast outwards and then recorded on an omnidirectional microphone to identify those frequencies that are returned.
Initially starting with broadcasting different tones, a number of frequencies were identified as predominant in the Chapel. These included 118Hz (approximately a B-flat 2 pitch) and 87Hz (around an F2) . Lucy commented, “The predominant frequency of 118Hz matched the calculations that we did beforehand, using the dimensions of the room, but I was not aware that this was going to sound like a B-flat! When we started to cut out certain frequencies in order to make others clearer, I wasn’t expecting some of the frequencies that came back, and some pitches were sounded in pairs, which created really interesting intervals. I hadn’t expected the actual ‘sounding out’ of the room to create such beautiful sounds just in itself.”
Lucy also tested what happened when a human voice was recorded and then broadcast out of the speakers, with the omnidirectional microphone then collecting the sound. The new input from the microphone was then used as output in the speakers, with a new input recording captured, until the frequencies started to achieve a consistent baseline of frequencies. The distortion which results loses any discernable voice or words, instead creating an eerie yet melodic electronic refrain.
The pitches that were sounded in the Chapel will form the basis of the pitches/notes Lucy will use when composing her piece. As she says, “I am going use some of the raw sounds we recorded from the experiment in a conversation with live acoustic instruments (Flute, Cello, and Piano). Hopefully, the Chapel will become a fourth instrument!”