Controllers for Alternative Scales
There’s nothing sacred about the arrangement of black and white levers that we know as the keyboard. It’s a very good musical interface for some purposes, not so good for others. The keyboard assumed its present configuration of seven white keys and five black keys per octave near the beginning of the 16th century, and has become such a universal gateway to all types of musical performance and production that it’s the reason this magazine exists. But if you’re exploring unusual types of music, you may want to consider using an unusual keyboard. I recently evaluated three such instruments that make playing alternate tunings and microtonal scales easier. Before looking at them, let’s explore why you’d want to do this in the first place.
Many books have been written about alternate tunings. (I recommend Harmonic Experience: Tonal Harmony From Its Natural Origins to Its Modern Expression by W. A. Mathieu.) Briefly, the three main branches of the tuning tree are historical and non-European tunings, equal temperaments, and just intonation. A terrific resource for exploring these is the free Scala soft ware available from huygens-fokker.org/scala. Using Scala, you can create any tuning you imagine, export it as a TUN file, and load it into a variety of soft ware synthesizers.
Just intonation. Just intonation is not a single tuning but a vast family. What all its members have in common is that the intervals are based on the whole-number ratios in the overtone series. A perfect fifth, for instance, is a frequency ratio of 3:2. A just major third has a ratio of 5:4. Some of the intervals in a scale based on just intonation will sound sweet and pure, while others may sound quite piquant or downright discordant. Some of the intervals will always be larger than others, so transposing a passage to a different key will change its quality in subtle or drastic ways. Just intonation scales can have as few or as many steps per octave as you like, which makes playing them on a 12-note-peroctave keyboard quite a challenge.
Equal temperament. In an equal-tempered scale, the ratio of pitches between adjacent keys is always the same, so you can transpose passages freely without changing their character. The octave (or some other interval, such as an octave plus a perfect fifth) is divided into some number of equal-size steps. Some equal-tempered scales, such as those with 12, 19, and 31 notes per octave, have intervals that are close to the perfect ratios of just intonation. (The 31-note scale is especially good but difficult to play on a 12-note-per-octave keyboard.) Other equal-tempered scales are more exotic, with tilted, dissonant thirds and fifths that resolve badly or not at all.
Musicians are always searching for fresh sounds. Yet for the past 250 years, one thing has remained the same: the 12-note-per-octave, equaltempered scale. Ever wonder why this is the case? The reasons are buried in history.
The earliest European keyboards (which were basically just banks of levers connected to bells or organ pipes) had only the white keys, plus Bb. Using these keys, you can play the modes of Gregorian chant. Sometimes the Bb was a black key, but on other keyboards it was at one end of the octave while the B natural was at the other end. That’s why some archaic note-lettering systems refer to Bb as H.
As the music of the Middle Ages became more complex, more black keys were added. But the intervals were not quite what we’re most familiar with today. Intervals from just intonation were the norm. When composers wanted to modulate temporarily to a distant mode, they needed black keys that would make proper intervals in that mode. Ab was not the same as G#, so some keyboards were built with split black keys, but these were difficult to build and play. As a result, compromise tuning systems were developed, which gave composers more options without the need for split black keys.
Our modern 12-note equal-tempered scale was the final compromise, and it has endured for more than 250 years, so it has been a good one—but it’s not perfect. The major third in 12-note equal temperament is about 14 cents too wide compared with the natural 5:4 ratio of a major third in just intonation. (A cent is one 100th of an equal-tempered semitone.) Our major thirds are somewhat bright and jangly, which may account in some small way for the restless, unsettled quality of the music written since this tuning was developed. Maybe composers and performers liked 12-note equal temperament because the culture they lived in was restless and unsettled from top to bottom. Now, we can explore other tunings with remarkable ease. Starting in the early 1980s, many synthesizers included user-programmable tuning tables. In the past few years, soft synths have made it easier than ever to explore the vast sonic resources of tunings. Anything from sweetly in-tune 11th chords to bizarre scales from outer space can be set up in just a few minutes.
Other Scales, Other Keyboards
One thing hasn’t changed, though: You’ll still be using a conventional MIDI keyboard. As long as you’re content to play music that uses a fixed set of 12 pitches per octave, that layout works, no matter what those pitches happen to be. You can retune individual notes up or down as needed, and the fingering patterns will remain the same in every octave. Even so, the arrangement of black and white keys can introduce confusion. Your scale might call for the perfect fifth up from C to be on the F# key rather than on the G key. (This happens when the 12 notes are tuned to overtones 12 through 24—an interesting scale, which Robert Rich has used on some of his CDs.) In that case, you’ll have to train your brain to interpret the keyboard in a new way.
If you want to play a scale that has, say, 19 or 31 notes per octave, the standard keyboard becomes a stumbling block. You can do it— I’ve done it—but it’s a brain-twister. Fluent transposing, wide chord voicings, and fast runs are close to impossible. So far, none of the major MIDI hardware manufacturers has built a keyboard that can easily be used with scales that require more than 12 notes per octave. Smaller companies, however, have stepped into the gap with their own designs.
Keyboards that have a uniform grid, either in a honeycomb or checkerboard layout, are close to ideal for alternate scales. You can use a single keyboard for many different tunings if you like; it’s not biased toward 12 notes per octave—nor, indeed, toward the octave as an interval. (If you’re curious what happens when you get rid of the octave, search online for “Bohlen-Pierce scale” and listen to some of the music you find.) With a uniform grid, the fingering of chords and melodic modes will be uniform no matter what root note you start on. That is, the keyboard will be isometric. The conventional 12-note keyboard, in contrast, is not isometric because every scale has a different arrangement of white and black keys, forcing us all to learn 12 different fingerings for the major scales alone.
Isometric button/grid surfaces include the Novation Launchpad, H-Pi Tonal Plexus, Monome, and Livid Instruments Ohm64 (reviewed June ’10). None of those, however, has velocity-sensitive buttons, which is why we haven’t devoted individual sections of this roundup to them. The Tonal Plexus TPX2 (above, top) lets you add velocity data to your performance using a foot pedal, but the less expensive U-Plex model (above, bottom) lacks this feature. The Launchpad, Monome, and Ohm64 are basically button banks—control surfaces with grids of non-velocity-sensing buttons. They’re good for triggering loops, but not for keyboard-style chords and leads unless you’re happy to hear all your notes at a fixed velocity.
Von Janko Lives!
While geared more for playing the usual 12-note scale than for scales with different numbers of notes per octave, the Von Janko keyboard layout (right) is isomorphic, meaning that chords and scales are fingered the same in every musical key. Once you learn the basic layout, your finger “muscle memory” works even if transposing a song from C to F#. Inventor Paul Vandervoort, profiled in Keyboard in December 1976, is trying to bring the Von Janko layout to market as the Daskin MIDI controller (daskin.com). The Harpejji (left) is a tapped string instrument whose isomorphic layout is similar (but not identical) to the Von Janko. Look for a full review of the Harpejji in an upcoming issue, and find out more at marcodi.com.
C-Thru Music AXIS-49
PROS Inexpensive. Highly portable.
CONS User keyboard mappings require external MIDI software.
PRICE (All direct from manufacturer) $495
PROS Separate pressure and Y-axis sensing for each finger is ideal for expressive playing, including polyphonic pitch-bends. Some internal sounds.
CONS Requires extended practice. Not much tactile feedback. Not compatible with all soft synths. No LCD.
PRICE (All direct from manufacturer) Full size: $5,290
Half size: $3,390
Starr Labs MICROZONE U-648
PROS Highly configurable keyboard layout. Left-hand joystick and knobs.
CONS Shallow key dip. Keys feel spongy, not snappy.
PRICE (All direct from manufacturer) $3,825
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