LiveScaler: Live control of the harmony of an electronic music track

TL;DR

This work tackles the challenge of live harmonic control in EDM, where performers lack direct access to a track's internal MIDI structure. It introduces LiveScaler, a real-time system that applies affine and periodic pitch transformations to all MIDI streams within Ableton Live via a two-component Max for Live architecture (Conductor and Instrument), leveraging the pitch-space framework $T\langle\alpha,\beta\rangle$ and the transformation form $A\langle\mu,\tau,\delta^-,\delta^+\rangle$. The paper formalizes the pitch-space and its transformations, details the implementation and live control mappings, and demonstrates the approach through an actual live performance (Escape), including a discussion of related work and potential extensions. The results show how harmonic manipulation of many channels can be achieved with immediacy and usability, enabling a practical live- performance workflow and suggesting paths toward broader integration with other DAWs, protocols, and musical parameters.

Abstract

In Electronic Dance Music (EDM), many artists use DJing techniques in order to perform their own productions live. As a consequence, they do not have access during the performance to the internal structure of their tracks, and specifically to their equivalent of a partition: MIDI files. On the other hand, if an artist attempts to remix or interpret their own production live, the number of tracks that they can simultaneously control is limited without suitable software. This article introduces LiveScaler, a software that allows live control of the harmony and pitch of electronic music. A set of pitch transformations, termed affine transformations, is presented. These transformations are applied to all MIDI streams of a prepared track. A MaxMSP implementation, in conjunction with Ableton Live, is proposed. Special attention is given to control issues, mapping, and practical live experimentation in the context of EDM.

Figures (9)

• Figure 1: La quantisation vers la gamme majeure est périodique sur l'octave : le même motif est répété sur chaque octave.
• Figure 2: La transformation $A \langle 1,2 \rangle : n \mapsto n + 2$ correspond à la transposition d'un ton vers l'aigu
• Figure 3: La transformation $A\langle -1,4\rangle :n\mapsto -n + 4$ avec $\alpha =$C$_5$ et $\beta = 12$
• Figure 4: L'image de la gamme de Do majeur par $A\langle -1,4 \rangle$ est un mode de Mi
• Figure 5: La transformation $A\langle 2,0\rangle :n\mapsto 2n$ permet d'obtenir des gammes apparentées à une gamme par tons.