TUNING SYSTEMS: Starting from Scratch
Before we get to Melody and Harmony, we have to start with the pitch tuning system, which gives us a super-set of notes from which to choose. From those pitches, we choose a scale; and then we choose (mostly) scale notes for melodies and chords. I think sometimes the terms tuning system and scale are used interchangeably. It is possible to create a tuning system that IS the scale you will use.
If we wanted to create a tuning system from scratch, we’d need to choose a set of frequencies. Imagine finding a harp with unbreakable strings. You could just start tuning it as you like within the range of your hearing.
Perhaps starting from the lowest note, you can listen to the relationships that are made when you play one note and tune the next. If you were going slowly and carefully, at some point you would probably stumble upon what we call an “octave”. Where some higher note is vibrating twice as fast as a lower note. This 2:1 ratio of frequencies has a distinct quality, every bit as pure sounding as a unison (1:1). You might also find ratios like 3:2 (“perfect 5th”) or 4:3 (“perfect 4th”) to be almost as pure sounding. But you could make some mischief and avoid anything pure sounding, if you want. It’s your scale.
After you have finished tuning all your notes; you can decide if that is your tuning system. If so, you then choose a subset of those notes to be your scale. Or, you can just decide that what you have tuned IS your scale.
In your scale, you can now make melodies by plucking one note at a time, or make chords by plucking any combination of notes at once. You will notice that some combinations sound “comfortable” and some sound “intense”. After that, the music you make, melodies and harmonies will create contours of comfort and intensity, which music theorists call “tension and release” (which sounds unnecessarily dirty, doesn’t it?).
The limitation is that your tuning system will work with that original set of notes, but if you want to shift everything higher or lower, the relationships might change as you move up one or more notes in your tuning/scale. The relationships are “fixed” at the original key.
Now with digital synths, there are several ways to create custom tunings/scales. A sampler app may allow you to create custom key maps where each key can have it’s own pitch. A standardized method for creating and exchanging tuning maps is called the “Scala” format. Some iOS synths (like Sunrizer and Z3+a) will allow you to load custom tunings using scala files.
In the next post, we’ll talk about our familiar 12-tone equal temperament tuning system.