Nightingale offers karaoke functionality by isolating vocals from instrumentals using the UVR Karaoke model or Demucs, with adjustable guide vocal volume. It features word-level lyrics transcribed and aligned by WhisperX, real-time pitch scoring with star ratings, and multiple player profiles for tracking individual score histories.

The GitHub repository provides a pure C implementation of the inference pipeline for Mistral AI's Voxtral Realtime 4B speech-to-text model, requiring only the C standard library. It features fast MPS inference, a chunked audio processing encoder to manage memory usage, and supports audio input from stdin or live microphone capture.