Chroma Features and Chromagrams Quiz

Answers and explanations appear as you take the quiz.

1. What does a standard twelve-bin chroma vector represent?
   • Twelve audio channels
   • Twelve Fourier bins spaced linearly by frequency
   • Pitch-class energy across twelve semitone classes
   • Twelve frequency-independent labels
2. What information does octave folding discard?
   • All pitch-class identity
   • Register or octave placement
   • Audio timing
   • Every amplitude value
3. Which transform may align naturally with semitone-spaced frequency bins?
   • A linear-frequency STFT grid with equal Hertz spacing
   • A cepstral grid representing spectral-envelope coefficients
   • A time-domain autocorrelation sequence indexed by lag
   • Constant-Q transform
4. Why can tuning deviation blur chroma energy across bins?
   • Pitch frequencies shift relative to the assumed reference
   • Octave folding guarantees every tuning shift disappears
   • The reference changes only the frame timestamps
   • A fixed pitch-class grid always matches every detuned recording
5. Which task benefits from comparing harmonic patterns across performances?
   • Measuring instrument timbre without spectral features
   • Detecting speech word boundaries
   • Comparing harmonic patterns across cover recordings
   • Estimating the duration of every individual note
6. Why can chroma alone be insufficient for exact chord identification?
   • Chroma retains every note's octave and duration
   • Different chords may share pitch classes while differing in voicing or context
   • It contains no frequency information
   • It always classifies percussion as harmony
7. What can frame normalization change in a chromagram?
   • Whether every recorded note has the same octave
   • Whether all instruments use equal tuning
   • Whether every frame is assigned a chord label
   • Whether values reflect relative pitch profile or absolute energy
8. Which settings should be recorded for reproducible chroma features?
   • Transform, tuning, normalization and hop length
   • Only the analysis window length
   • Only the target class labels
   • Only the absolute tuning reference