Lecture: Tempo and Beat Tracking¶
After working through the material of this lecture, you should be able to answer the following questions:
- What is the relation between beat and tempo?
- What is the goal of onset detection? What are important signal characteristics exploited for onset detection? What are main challenges in onset detection?
- What is the main idea of energy-based novelty detection? What is a novelty function? What is the role of half-wave rectification?
- What is the main idea of spectral-based novelty detection? (See Eq. 6.6, Eq. 6.7, and Eq. 6.8.)
- Why is the role of logarithmic compression? (See Eq. 6.5.)
- What is the unit of a beat or pulse rate? What do measure, tactus, and tatum refer to?
- What does a tempogram representation encode?
- How can one compute a tempogram using Fourier analysis? (See Eq. 6.25 and Eq. 2.26.)
- How can one compute a tempogram using Autocorrelation analysis? What is the relation between lag and tempo? (See See Eq. 6.29, Eq. 6.30, and Eq. 6.31).
- What are tempo harmonics and tempo subharmonics? What is the main difference between Fourier and autocorrelation tempograms? (See Table 6.2.)
- How can one compute the predominant local pulse (PLP) information from a Fourier tempogram and its phase? (See Eq. 6.36 to Eq. 6.39.)
- What does the amplitude of a PLP function encode?