title: Extracting audio features
body: <p>I am working on extracting features from an audio file to build a recommendation system.</p>
  <p>So far I am able to extract tempo, beat-times, loudness and pitch class using librosa and ffmpeg.</p>
  <p>My question how we can extract/detect features as Danceability, Energy, Acousticness, Speechiness, Valence without using Spotify API. Are there any libraries or algorithm using which we can do so.</p>