The SalMar Construction was not 'easy-to-use' and there is evidence showing that this is one of its strong points. Although an HCI for music needs to be designed so that the user can interact with it successfully to make music, it is not essential, and indeed probably a bad thing, for it to be too simple. An over-simplified HCI is easy to make some noise on initially that sounds musical, but after making basic progress, further adventure is very hard. The most common question Martirano was asked was "Do you know what it will do next?". The answer was that he knew what he had to do to alter the sounds, but trying to analyse it was too complex a task. The algorithm was complicated, and while this made it difficult to explain, it gave greater opportunity for the performer to investigate different sounds.
Dr Andy Hunt at the University of York reinforces this idea. In a study of 3 HCIs, the three each had different complexities of mapping of inputs to sound generation. In the same way that the position of the lips of a flautist can affect pitch, timbre and volume, the more complicated mapping allowed a single part of the HCI to change a number of musical parameters. Hunt found that although the simpler systems were easy to make a sound on to start with, they soon became boring to use, and the subjects stopped wanting to use them. Remember the two points from before:
The more complex systems engaged the imagination in a way the simpler ones didn't. The fact that a larger amount of effort (more of the active skill) had to be used to manipulate the sounds meant that the imagination became engaged. This led to the users wanting to practice, and then the practice meant that they were able to produce sounds that would have been far harder to do with the simple interface.
This shows that developing a successful HCI is not just a matter of finding a simple way for users to interact with the computer - it is more complex, and involves the right mix of complexity to interest the player, without being so confusing that random noise is generated. HCI techniques are developing all the time, and the music that can be produced by different HCIs is becoming more varied.