essentiaRT~ is a real-time subset of Essentia (MTG's open-source C++ library for audio analysis and audio-based music information retrieval) implemented as an external for Pd and Max/MSP. As such, the current version does not yet include all of Essentia’s algorithms, but a number of features to slice and provide on-the-fly descriptors for classification of audio in real-time. In the context of the GiantSteps EU-funded project, we expect to add further functionalities, including (but not being limited to) more algorithms currently in Essentia.