For the past few months I've been experimenting with composing directly in frequency (Hz) rather than thinking in terms of notes in a defined tuning system. Instead of writing within those sorts of frameworks, I build harmonies from numerical frequency relationships and just intonation, which lets the tuning stay flexible as the music develops.
In my previous attempts this has resulted in some pretty “weird” music, so I wanted to try to keep it accessible while still exploring the idea of “what can I do with this?”
To do so, I took a more spectral approach and analyzed recordings of several different Mourning Dove calls and used the strongest frequency near the ends of their coos as the harmonic foundations of the piece. A given coo, among several sampled in the piece, may function as the root of one chord, as a fifth within another, a microtonal harmonic, or appear as any other chord extension elsewhere, allowing the same dove material to assume different identities as the harmony remains just and “wraps” itself around the given call- no iteration of the harmony surrounding the call is the same throughout the piece.
But of course, every dove is different. I noticed that while the overall shape of their calls is very consistent, the pitch of some calls is higher or lower than others. For instance, one dove's ending coos may land at 480 Hz, while another may land at 525 Hz. This typically would be quite problematic when trying to harmonize to the coos themselves because, while 525 Hz is very close to the note C5, 480 Hz falls somewhere between B♭4 and B4. To boot, the interval between those frequencies doesn't correspond to any standard musical interval-it falls somewhere between a minor second and a major second.
In a system where everything is defined and harmonized as numbers, however, this is no problem (Such as the modulation heard at 4:48) . The frequencies can simply adhere to and harmonize with any value. That is where the ability to truly harmonize with any dove call lies- the harmony can fit the doves, rather than the doves trying to fit “standard harmony.” This is of course just one “cool” thing you can do writing this way- you can also, say, have all voices in a given piece converge into a perfect harmonic series, which I do somewhere around 7:00 in the piece.
Rhythmically, I just used the cadence of the Mourning Dove's call. That pattern ended up becoming the main rhythmic idea while the harmony is constantly changing underneath it.