# The Effect of Isomorphic Pitch Layouts on the Transfer of Musical Learning +
## 1 Introduction
### Current Study  
The above advantages of isomorphic layouts have been proposed since the nineteenth century [20; 21; 22]; however, despite this long history and the recent development of multiple music interfaces utilising isomorphic pitch layouts (e.g., Array Mbira [23], Thummer [14], AXiS-49 [11], Musix Pro [24], LinnStrument [12], Lightpad Block [13], Terpstra [25]), no study has directly compared isomorphic and non-isomorphic layouts. To address this long-standing, but untested suggestion, in this study, we investigated whether the learnability and playability of a musical instrument increase with the use of isomorphic pitch layouts both within and, crucially, across keys. In doing so, we aimed to extend the research done by [15] to clarify cognitive and sensory-motor aspects of playing instruments in order to inform the design of musical instruments that facilitate learning. Participants were tested on two variants of two well-established pitch layouts: the Wick layout [20] and the Bosanquet layout [21; 26]. In each case, one version of each type of layout was isomorphic (i.e., in its standard form), while another was slightly adjusted to make it non-isomorphic. The resulting four layouts are detailed in Section 2.2 and Figures 5-8. These layouts are also all broadly congruent with the SMARC (spatial-musical association of response codes) effect. The SMARC effect is a phenomenon described by [PERSON] et al. [27] whereby pitch is mapped on a spatial representation such that high pitches correspond to upward right-hand positions and low pitches correspond to downward left-hand positions. This effect is similar to the SNARC (spatial-numerical association of response codes) effect described by [PERSON], [PERSON] and [PERSON] [28], which maps numbers in the same way. The pitches on the Wicki-like and Bosanquet-like layouts ascend in an upwards direction and a rightwards direction, respectively. While congruency with this effect was not examined in this study, it does have implications for the learnability of pitch layouts. Ensuring the layouts tested in this study were congruent with the SMARC effect was done to eliminate it as confounding variable. All layouts also had adjacent major seconds. This is a factor that, as previously mentioned, has already been established to impact learnability and playability [15], so, like the SMARC effect, it is helpful that the chosen layouts eliminate this as a potential confound. It should be noted that a comparison of the two broad layout types (that is, Wicki vs. Bosanquet) was not of primary interest in this study, but, instead, the use of two different layout types facilitated an exploration of whether or not any general benefits of isomorphism occurred. The Wicki layout has been used previously in the development of the [PERSON] musical interface and in Wicki-Hayden concertinas. The Bosanquet layout has been examined with reference to its isomorphic properties since 1877 [21] (here, [PERSON] specifically suggested that the arrangement of keys on [PERSON]'s keyboard reduces the number of chord forms a player must learn), and has been implemented in various slightly different forms in a variety of instruments, such as the [PERSON] keyboard. As in [PERSON] and [PERSON] [15], this study utilised a series of tasks on a multi-touch tablet (see Figure 1 in Section 2.2) involving exercises typically used in the teaching of musical instruments, namely scales and arpeggios. These exercises are useful in music learning because they relate to how musical pieces are structured, and they introduce learners to the different intervals between pitches. For example, scales are made up of major and minor seconds, which are the most common intervals found in Western melodies. Similarly, arpeggios are made up of major and minor thirds, and perfect fourths, which occur frequently in harmonies and bass lines, respectively. The scale and arpeggio tasks served to teach participants where pitches lie in relation to each other on the novel musical interface.