Do paired, symmetrical keyboards offer the player an advantage?

How well can symmetrical musical keyboards help the player learn to play an instrument. 

In summary, one side learns to play a musical exercise, the other side of the body learns to play the piece at about 2/3 note accuracy (for the same speed of play) or conversely can be brought up to the same level of note accuracy with 1/3 more practicing with the second side.

 This applies to both the temporary skill one gains in an hour’s practice and to long-term, hard-wired movements, the skill developed over weeks of practice.

To a first approximation, keyboard skills transferred equally well both ways, from right to left and vice-versa, as some of the recent scientific literature reports.

Symmetry offers other advantages that are discussed more informally in this article. .

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Experiment Background

The standard music keyboard and all other popular musical instruments are completely asymmetrical: between the left and right hands, different fingers must play any given note, and due to the substantially different reach of the thumb and little finger, each hand’s movement varies as well.

Experiment Hypothesis

With compact ergonomic keyboards is it is possible to make the fingering symmetric, that is to make the motion of each hand and finger mirror-imaged along the left-right axis.
Jim Plamondon proposed this for his two-keyboard Thummer, which did not make it to market.

Figure 1: Jim Plamondon's "Thummer" keyboard prototype, a symmetrical design

Non-musical skills are well known to transfer from hand to hand (1).

In theory, a symmetrical musical instrument would greatly reduce the amount to learn and speed learning. To what degree does this really happen in practice?

Figure 2: Playing the same notes with the same fingers of each hand. Note that the middle finger is used to play the root note of the piece (i.e. C)

Experiment design

The test subject is the author, who cannot play a regular keyboard and began to learn to play a symmetrical keyboard instrument about 2-3 years ago. The subject can read musical scores enough to assist in choral singing.

The test instrument is a jammer keyboard constructed from 2 Axis-49 keyboards and some software to remap the notes to the Wicki-Hayden note layout. The instrument’s keys have been recolored in order to simplify navigation (e.g. all C’s are colored green). Each keyboard has 98 keys and is roughly equivalent to a complete 88-key keyboard under each hand. The midi signals generated are mapped to a piano sound (Kontact 5’s New York Grand). The latency is small, about 10 msec.  {insert picture of jammer}

The test instrument is not completely symmetrical, due to the limitations of the Axis-49. However, it is symmetrical in the whole active play area of the exercises played.

The test presentation and measurements were done by the program Piano Marvel, a piano learning software package. The program has a large set of exercises (usually portions of a popular song), ranked in increasing order of difficulty. It presents the songs on screen as a traditional musical score and plays the exercise onscreen and audibly. The student must play the notes exactly in time with the score and the program notes mismatches or missed notes, and presents and records the percentage of correct keystrokes.

The test process was to learn to play a given exercise with one hand, first noting the beginning accuracy level of each hand (initially usually low; under 30%; close to the 15% expected by random chance).

A variety of combinations of hand practice combinations were tried. For testing symmetrical learning, a single hand would practice up to the 96%-100% (Gold) level, and then the other hand would be trained up to the same level, first noting the proficiency level of the new hand. Time needed to bring the second hand up to gold proficiency was estimated subjectively.

Experimental data gathered

Selection of experimental test cases

In the Piano Marvel course there are two banks of exercises labelled “Method” and “Technique”. The default set, “Method”, contains mostly songs or snippets of songs. At the time of this study, the author had concentrated on the “Method” bank of test exercises, and passed most of its second level of exercises.

The “Technique” set contains mostly technical exercises, which had not been attempted. The author experimented with learning the first level (1-A through 1-E and some of level 2) of courses, over 100 exercises, learning to play each with both hands, while varying the order of hand usage.

Other considerations

The author’s non-preferred hand is less fast and accurate, for some moves, than the preferred hand. This confuses the comparison of skill levels between hands.

The skill level is not linearly related to note accuracy: an accuracy of 80% is not 10% better than a level of 70%, nor is a level of 96% 5% better than a level of 91%.  For this reason, comparison was between base-line (starting) skill levels and 96%-100% accuracy end-point.

The practice goal also included the need to not favor just the preferred hand; to efficiently train the NP hand’s speed and accuracy as well.

Initial experiments

When preferred hand learns first

When a Piano Marvel exercise was learned to 100% accuracy with the Preferred (right) hand (from less than 25% accuracy with either hand), the NP (left) hand could usually play 60-70% of the notes correctly at the same speed.

The left hand then was able to get to 100% accuracy in about 1/3 the time. For example, when training the right hand took three hours, then training the left hand to the same speed and accuracy took only about an hour. Most exercises took less than an hour to pass.

Curiously, this training of the left hand further improved the right hand. For example, after the left hand learned to play the exercise at 100 beats per minute, the right hand could play up to 110 beats per minute.

When both hands learns at same time

Alternating right hand and left hand practice in a single exercise was possible, but sometimes was slowed by confusion in the position and direction needed to mirror-image play.  

When non-preferred hand learns first - author’s recommendation

Taking into account the lesser skill level of the non-preferred (NP) hand and the need to build up its skill, the best way to learn a given exercise seemed to be:

1. Work out the initial fingering with the NP hand, the author’s left. This takes longer, but gives the NP hand more practice learning fingering.
2. Practice the piece with the NP hand, maintaining a speed level where about 80% or more of the notes are correct, gradually increasing the speed until the “Gold piano” (no important mistakes made, equivalent to an A letter grade) is won at the game’s goal speed.
3. Switch to the preferred hand and repeat the practice session, increasing the speed to 10% beyond Piano Marvel’s goal speed.

This approach, the author found, gives a better workout to the less-proficient hand. The preferred hand then picked up the exercise quickly (sometimes starting at an accuracy level of 80%), so once 100% accuracy was achieved, extra practice at a higher speed was needed to give the hand enough practice. Learning with both hands also seemed to solidify the learning; less skill seemed to be lost the next day.

Done this way, learning to play either hand on a symmetrical keyboard was little more work.

Other findings: clumsiness transfers too

The author has noted occasions of “clumsiness transfer” as well as “skill transfer”. For example, if the P hand learned, the theme for “Chariots of Fire”, then trying to play it with the other hand would be reasonably successful, but some notes would be missed.

Then when practice switched to the original hand, it then made the same mistakes the other hand had just made. Apparently “un-skills” can travel from the hand to hand just as skills do.

This should be investigated.

The author found “clumsiness transfer” faded with time, with no conscious effort required ; presumably my sub-conscious learned to transfer the preferred way.

Conclusion

This test confirmed the hypothesis that symmetrical musical keyboards offer the player the advantage of skill transfer between sides of the body. The test quantified the skill transfer: if one side learns to play a musical exercise, the other side of the body learns to play the piece at about 2/3 note accuracy (for the same speed of play) or conversely can be brought up to the same level of note accuracy with 1/3 more practicing with the second side.

 This applies to both the temporary skill one gains in an hour’s practice and to long-term, hard-wired movements, the skill developed over weeks of practice

To a first approximation, keyboard skills transferred equally well both ways, from right to left and vice-versa, as some of the recent scientific literature reports.

Symmetry offers other advantages that are discussed, more informally here.

NOTES

1. Stoeckel T, Weigelt M. Brain lateralisation and motor learning: Selective effects of dominant and non-dominant hand practice on the early acquisition of throwing skills. Laterality: Asymmetries of Body, Brain and Cognition. 2011;17(1):18–37.

Key Quote: “Participants initially practising with their dominant hand benefited more from practice than participants beginning with their non-dominant hand. These results indicate that spatial accuracy tasks are learned better after initial practice with the non-dominant hand, whereas initial practice with the dominant hand is more efficient for maximum force production tasks.”

2. Matias Edgar,  MacKenzie I. Scott, William Buxton  Half-QWERTY: a one-handed keyboard facilitating skill transfer from QWERTY. CHI '93 Proceedings of the INTERACT '93 and CHI '93 Conference on Human Factors in Computing Systems. 1993,  pp 88-94

“During the evaluation of a one-handed chord keyboard, Rochester, Bequaert, and Sharp [17] trained one student using the right hand only. The subject was later retrained to type with the left hand only. The subject ‘reached close to his right-hand typing speed in less than one third the time he spent learning right-handed typing’”

3. Teixeira L, Timing and Force Components in Bilateral Transfer of Learning. Brain and Cognition 44, 455–469 (2000) doi:10.1006/brcg.1999.1205, http://www.smpp.northwestern.edu/savedLiterature/Teixeira2000BrainAndCognition44p.455-469.pdf

“… bilateral transfer of learning took place for both anticipatory timing and force control, with more noticeable transfer of training for the former.”