Library specification 8 out of 19 progressions selected among the common ones (from: https://en.wikipedia.org/wiki/List_of_chord_progressions ). See file readme.pdf. Chord progressions have been recorded on piano. For each progression there are three versions with different tempo: 90bpm; 120 bpm; 150 bpm. The midi files can be used to elicit emotions. The corresponding brainwaves have been collected by a Brain-Computer Interface and then classified following Russell’s Valence/Arousal model (Russell, 1980) (Russell, 1980).
Reference: J.A. Russell, “A circumplex model of affect”, Journal of personality and social psychology, Dec, 39(6):1161, 1980