The ACCompanion v0.1: An Expressive Accompaniment System

The ACCompanion is an expressive accompaniment system for MIDI input. The system uses a probabilistic monophonic score follower to track the position of the soloist in the score, and a linear Gaussian model to compute tempo updates. The expressiveness of the system is powered by the Basis-Mixer, a state-of-the-art computational model of expressive music performance. The system allows for expressive dynamics, timing and articulation.

The ACCompanion is developed by a joint team of researchers from the Austrian Research Institute for Artificial Intelligence (OFAI), the Johannes Kepler University Linz (JKU) and the University of Music and Performing Arts Vienna (MDW).


In the following videos, the piano roll shows the notes performed by the soloist in green and the accompaniment in purple. Wrong notes performed by the soloist are displayed in red. The intensity of the colors in the piano roll corresponds to the loudness of the performed notes. The performance errors by the soloists are deliberate to showcase the capabilities of the system.

These videos were recorded at the University of Music and Performing Arts Vienna, Austria.