Replacing Keyboards: Adventures Across the Fourths Dimension

Has the Fourths String Layout become a new standard for finger positioning?

Most electronic music today is played on a MIDI piano keyboard. This layout has been the most popular note arrangement for technological instruments since the early days of pipe organs. The linear, side-by-side nature of keyboards lends itself well to controlling electronic sound because it is easily adapted to the use of electronic switches. It’s also a simple note arrangement to learn because it accentuates the diatonic scale over the accidentals, making it easy to play music in major and minor keys by playing only the white keys.

The Trouble with Keyboards

However, the venerable piano note arrangement has a few big problems. The pitch intervals aren’t uniformly spaced, and the black keys are located behind the white keys. In other words, it’s not isomorphic. That means for each chord or scale, you must learn a different fingering for each of the twelve keys.

The standard keyboard layout presents several problems for the new crop of expressive MPE controllers (like my LinnStrument), in which the most natural way to bend pitch is to slide your finger directly from one note region to another. The main problem is that the distance and direction of pitch bends are different, depending on which pitches you’re bending between and which musical key you’re playing in. For example, a minor-third bend from C to E flat is a rearward diagonal movement, while a whole step bend from E flat to F is a diagonal frontward movement.

A related problem is that vibrato, performed on an expressive controller by wiggling your finger left and right, is asymmetrical. For example, if you perform vibrato on a C key, wiggling to the right toward the D key will produce twice the pitch change as wiggling to the left toward the B key.

Because a standard keyboard has only one instance of each pitch, you can’t easily play chords and melody in the same pitch range. And there’s often only one correct way to finger a chord or scale.

Another problem is that the pitches are all arranged in a single line. For two-handed play, this makes it difficult to watch both hands because they may be far apart. The standard keyboard layout also makes for a long instrument that isn’t very portable. This linear arrangement was necessary a few centuries ago when a string was needed behind each key, but that’s no longer relevant on electronic keyboards.

Given all these problems, some people are beginning to view the venerable piano keyboard as a little long in the tooth and perhaps in need of replacement. A variety of alternate note arrangements have been proposed over the years, including the button accordion, the Jankó keyboard, hex-key layouts like the Harmonic Table, the Jammer, and others. Each has merits, and you can learn about these in a web search if you’d like to learn more.

Enter the Fourths String Layout

In my LinnStrument, I abandoned the piano keyboard entirely in favor of something called the Fourths String Layout (see the opening diagram). This layout arranges pitches as on a stringed instrument, with multiple rows consisting of consecutive semitones. As with strings, you can tune the rows however you like, but the most popular tuning is all musical fourth intervals, an interval of five semitones between rows. And similar to the white and black keys of a piano, LinnStrument lights the C major scale notes, lighting each C note in a different color.

The Fourths String Layout overcomes all of the piano’s problems.

It is isomorphic, meaning that for a given chord or scale, you can use the same fingering in all twelve keys. Just slide your hand left, right, or to other rows.

Bending pitches is always the same distance and direction for a given pitch change regardless of musical key. To slide from C to D, you simply play the C note pad then slide right to the D note pad. For vibrato, simply wiggle your finger for a vibrato that is perfectly symmetrical because the semitones are uniformly spaced.

Like any stringed instrument, it has multiple instances of the same pitch on different rows. That makes it easy to play chords and melody in the same pitch range and in different areas of the playing surface. You can also choose between multiple ways to finger a chord or scale, just as on guitar.

Instead of one long row of pitches, the multiple rows of overlapping pitches permit two-handed play with both hands relatively close together, like two-handed tapping on a guitar. Consequently, it’s easy to watch both hands at the same time. The overlapping rows make for a very portable instrument, giving the same pitch range as a 5-octave piano keyboard in about half the length.

By the way, the Fourths String Layout wasn’t my idea. Some jazz guitarists tune their guitars is all fourths, reporting that it makes complex parts easier to play than standard guitar tuning. But perhaps more importantly, it’s the standard note arrangement for Ableton Push, Roli’s LightPad Block, the onscreen keyboard in Bitwig Studio, the iPad app GeoShred from Mo Forte, the iPad app Musix Pro, the MPE controller Madrona Labs SoundPlane, the French MPE controller Joué, the Starr Labs Z-Board, and more. This growing acceptance suggests that the Fourths String Layout is gradually becoming a new standard note arrangement for electronic instruments.

What’s it like to play this layout? Here’s a video that shows what LinnStrument players are doing with it.

LinnStrument players often report that it is easier to learn chords and scales because the isomorphism allows the same fingerings to be used for all keys. They tend to think more in relative than absolute pitch. For the same reasons, they also report that expressive gestures are easier to perform, especially stringed-instrument gestures. In addition, the multiple instances of each pitch add versatility in fingering chords or scales. They say the layout leads them in new and surprising musical directions.

Over time, I expect the popularity of this new note layout to grow. Who knows? Perhaps some day it may even overtake the piano layout in popularity.