Interactive music system based on pitch quantization and tonal navigation

Recent developments in the field of human computer interaction have led to new  ways of making music using digital instruments. The new set of sensors available  in  devices  such  as  smartphones  and  touch  tablets  propose  an  interesting  challenge in  the  field of music  technology  regarding how they can be used in a  meaningful and musical way. One to one control over parameters such as pitch,  timbre and amplitude is no longer required thus making possible to play music  at a different level of abstraction.  Lerdahl and Jackendoff presented in their publication “Generative theory of tonal music”  a  perspective  that  combines  Heinrich  Schenker’s  theory  of  music  and  Noam  Chomsky  linguistics  to  explain  how  tonal  music  is  organized  and  structured. This idea opens up the possibility of investigating ways to manipulate  a  “wider”  aspect  of  music  through  an  assisted  interactive  musical  system  that  takes  into  account  the  “principles”  or  common  knowledge  used  in  music  composition and performance. Numerous publications exist in the field of music  theory regarding how the tonal aspect of music works. Due to aspects related to  psychoacoustics and cultural inheritance, there is a certain common base on how  to  form  and  use  chords  and  scales,  and  how  they  are  organized  in  terms  of  hierarchies, movement tendencies and tonal functions. This project deals with the design of a graphical representation about the use of  tonality in jazz and popular music, organizing chords and scales in a hierarchical,  semanticall and practical way.  This representation, which we call “Tonal map”, is  then used  as  the  graphical  interface  of  an  interactive  system  to  manipulate  different  data  types in  realItime.  The  process  consists in adjusting note  values  (pitches)  using  a  set  of  rules  that  characterize  each  sector  of  the  graphical  representation.    The  output  produced  by  system  is  the  “tonally  quantized”  version of the input data using as transformation parameter the set of rules that  the user chooses through the graphical interface.  The  graphical  model  was  constructed  using  different  methods  for  learning  modern harmony and taking also into account models of music perception and  cognition. The interactive system was implemented through a Max for Live patch  that works as a MIDI effect.  Input data is  first  transform into MIDI note events  that  are  modified  according  to  the  users  selection  in  the  tonal  map.  The  hardware interface uses a Wacom tablet with a printed version of the tonal map.  The interaction can be seen as a tonality selector for real time transformations of  MIDI data. The prototype can also be used with several inputs at the same time  allowing collaborative playing