diff --git a/1- Overview/Audio Signal Processing for Machine Learning .pdf b/01 - Overview/Audio Signal Processing for Machine Learning .pdf similarity index 100% rename from 1- Overview/Audio Signal Processing for Machine Learning .pdf rename to 01 - Overview/Audio Signal Processing for Machine Learning .pdf diff --git a/2- Sound and waveforms/2- Sound and waveforms.pdf b/02 - Sound and waveforms/2- Sound and waveforms.pdf similarity index 100% rename from 2- Sound and waveforms/2- Sound and waveforms.pdf rename to 02 - Sound and waveforms/2- Sound and waveforms.pdf diff --git a/3- Intensity, loudness, and timbre/Intensity, loudness, and timbre.pdf b/03 - Intensity, loudness, and timbre/Intensity, loudness, and timbre.pdf similarity index 100% rename from 3- Intensity, loudness, and timbre/Intensity, loudness, and timbre.pdf rename to 03 - Intensity, loudness, and timbre/Intensity, loudness, and timbre.pdf diff --git a/3- Intensity, loudness, and timbre/intensity_and_timbre.ipynb b/03 - Intensity, loudness, and timbre/intensity_and_timbre.ipynb similarity index 100% rename from 3- Intensity, loudness, and timbre/intensity_and_timbre.ipynb rename to 03 - Intensity, loudness, and timbre/intensity_and_timbre.ipynb diff --git a/4- Understanding audio signals/Understanding audio signals.pdf b/04 - Understanding audio signals/Understanding audio signals.pdf similarity index 100% rename from 4- Understanding audio signals/Understanding audio signals.pdf rename to 04 - Understanding audio signals/Understanding audio signals.pdf diff --git a/5- Types of audio features for ML/Types of Audio Features for ML.pdf b/05 - Types of audio features for ML/Types of Audio Features for ML.pdf similarity index 100% rename from 5- Types of audio features for ML/Types of Audio Features for ML.pdf rename to 05 - Types of audio features for ML/Types of Audio Features for ML.pdf diff --git a/6- How to extract audio features/How to extract audio features .pdf b/06 - How to extract audio features/How to extract audio features .pdf similarity index 100% rename from 6- How to extract audio features/How to extract audio features .pdf rename to 06 - How to extract audio features/How to extract audio features .pdf diff --git a/7- Time-domain audio features/Time-domain audio features.pdf b/07 - Time-domain audio features/Time-domain audio features.pdf similarity index 100% rename from 7- Time-domain audio features/Time-domain audio features.pdf rename to 07 - Time-domain audio features/Time-domain audio features.pdf diff --git a/8- Implementing the amplitude envelope/Implementing the amplitude envelope.ipynb b/08 - Implementing the amplitude envelope/Implementing the amplitude envelope.ipynb similarity index 100% rename from 8- Implementing the amplitude envelope/Implementing the amplitude envelope.ipynb rename to 08 - Implementing the amplitude envelope/Implementing the amplitude envelope.ipynb diff --git a/20- Extracting MFCCs with Python/audio/debussy.wav b/08 - Implementing the amplitude envelope/audio/debussy.wav similarity index 100% rename from 20- Extracting MFCCs with Python/audio/debussy.wav rename to 08 - Implementing the amplitude envelope/audio/debussy.wav diff --git a/23- Spectral centroid and bandwidth/audio/duke.wav b/08 - Implementing the amplitude envelope/audio/duke.wav similarity index 100% rename from 23- Spectral centroid and bandwidth/audio/duke.wav rename to 08 - Implementing the amplitude envelope/audio/duke.wav diff --git a/23- Spectral centroid and bandwidth/audio/redhot.wav b/08 - Implementing the amplitude envelope/audio/redhot.wav similarity index 100% rename from 23- Spectral centroid and bandwidth/audio/redhot.wav rename to 08 - Implementing the amplitude envelope/audio/redhot.wav diff --git a/9- RMS energy and zero-crossing rate/RMS Energy and Zero-Crossing Rate.ipynb b/09 - RMS energy and zero-crossing rate/RMS Energy and Zero-Crossing Rate.ipynb similarity index 100% rename from 9- RMS energy and zero-crossing rate/RMS Energy and Zero-Crossing Rate.ipynb rename to 09 - RMS energy and zero-crossing rate/RMS Energy and Zero-Crossing Rate.ipynb diff --git a/23- Spectral centroid and bandwidth/audio/debussy.wav b/09 - RMS energy and zero-crossing rate/audio/debussy.wav similarity index 100% rename from 23- Spectral centroid and bandwidth/audio/debussy.wav rename to 09 - RMS energy and zero-crossing rate/audio/debussy.wav diff --git a/8- Implementing the amplitude envelope/audio/duke.wav b/09 - RMS energy and zero-crossing rate/audio/duke.wav similarity index 100% rename from 8- Implementing the amplitude envelope/audio/duke.wav rename to 09 - RMS energy and zero-crossing rate/audio/duke.wav diff --git a/14- Extracting the Discrete Fourier Transform/audio/noise.wav b/09 - RMS energy and zero-crossing rate/audio/noise.wav similarity index 100% rename from 14- Extracting the Discrete Fourier Transform/audio/noise.wav rename to 09 - RMS energy and zero-crossing rate/audio/noise.wav diff --git a/8- Implementing the amplitude envelope/audio/redhot.wav b/09 - RMS energy and zero-crossing rate/audio/redhot.wav similarity index 100% rename from 8- Implementing the amplitude envelope/audio/redhot.wav rename to 09 - RMS energy and zero-crossing rate/audio/redhot.wav diff --git a/9- RMS energy and zero-crossing rate/audio/voice.wav b/09 - RMS energy and zero-crossing rate/audio/voice.wav similarity index 100% rename from 9- RMS energy and zero-crossing rate/audio/voice.wav rename to 09 - RMS energy and zero-crossing rate/audio/voice.wav diff --git a/10 - Fourier Transform: The Intuition/Demystifying the Fourier Transform The Intuition.pdf b/10 - Fourier Transform_The Intuition/Demystifying the Fourier Transform The Intuition.pdf similarity index 100% rename from 10 - Fourier Transform: The Intuition/Demystifying the Fourier Transform The Intuition.pdf rename to 10 - Fourier Transform_The Intuition/Demystifying the Fourier Transform The Intuition.pdf diff --git a/10 - Fourier Transform: The Intuition/Fourier Transform .ipynb b/10 - Fourier Transform_The Intuition/Fourier Transform.ipynb similarity index 100% rename from 10 - Fourier Transform: The Intuition/Fourier Transform .ipynb rename to 10 - Fourier Transform_The Intuition/Fourier Transform.ipynb diff --git a/10 - Fourier Transform: The Intuition/audio/piano_c.wav b/10 - Fourier Transform_The Intuition/audio/piano_c.wav similarity index 100% rename from 10 - Fourier Transform: The Intuition/audio/piano_c.wav rename to 10 - Fourier Transform_The Intuition/audio/piano_c.wav diff --git a/12- Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.ipynb b/12 - Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.ipynb similarity index 100% rename from 12- Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.ipynb rename to 12 - Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.ipynb diff --git a/12- Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.pdf b/12 - Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.pdf similarity index 100% rename from 12- Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.pdf rename to 12 - Defining the Fourier transform using complex numbers/Defining the Fourier Transform Using Complex Numbers.pdf diff --git a/13- Discrete Fourier Transform/Discrete Fourier Transform.pdf b/13 - Discrete Fourier Transform/Discrete Fourier Transform.pdf similarity index 100% rename from 13- Discrete Fourier Transform/Discrete Fourier Transform.pdf rename to 13 - Discrete Fourier Transform/Discrete Fourier Transform.pdf diff --git a/14- Extracting the Discrete Fourier Transform/Visualising the Power Spectrum.ipynb b/14 - Extracting the Discrete Fourier Transform/Visualising the Power Spectrum.ipynb similarity index 100% rename from 14- Extracting the Discrete Fourier Transform/Visualising the Power Spectrum.ipynb rename to 14 - Extracting the Discrete Fourier Transform/Visualising the Power Spectrum.ipynb diff --git a/9- RMS energy and zero-crossing rate/audio/noise.wav b/14 - Extracting the Discrete Fourier Transform/audio/noise.wav similarity index 100% rename from 9- RMS energy and zero-crossing rate/audio/noise.wav rename to 14 - Extracting the Discrete Fourier Transform/audio/noise.wav diff --git a/14- Extracting the Discrete Fourier Transform/audio/piano_c.wav b/14 - Extracting the Discrete Fourier Transform/audio/piano_c.wav similarity index 100% rename from 14- Extracting the Discrete Fourier Transform/audio/piano_c.wav rename to 14 - Extracting the Discrete Fourier Transform/audio/piano_c.wav diff --git a/14- Extracting the Discrete Fourier Transform/audio/sax.wav b/14 - Extracting the Discrete Fourier Transform/audio/sax.wav similarity index 100% rename from 14- Extracting the Discrete Fourier Transform/audio/sax.wav rename to 14 - Extracting the Discrete Fourier Transform/audio/sax.wav diff --git a/14- Extracting the Discrete Fourier Transform/audio/violin_c.wav b/14 - Extracting the Discrete Fourier Transform/audio/violin_c.wav similarity index 100% rename from 14- Extracting the Discrete Fourier Transform/audio/violin_c.wav rename to 14 - Extracting the Discrete Fourier Transform/audio/violin_c.wav diff --git a/19- MFCCs Explained Easily/Mel-Frequency Cepstral Coefficients Explained Easily.pdf b/19 - MFCCs Explained Easily/Mel-Frequency Cepstral Coefficients Explained Easily.pdf similarity index 100% rename from 19- MFCCs Explained Easily/Mel-Frequency Cepstral Coefficients Explained Easily.pdf rename to 19 - MFCCs Explained Easily/Mel-Frequency Cepstral Coefficients Explained Easily.pdf diff --git a/20- Extracting MFCCs with Python/Extracting MFCCs.ipynb b/20 - Extracting MFCCs with Python/Extracting MFCCs.ipynb similarity index 100% rename from 20- Extracting MFCCs with Python/Extracting MFCCs.ipynb rename to 20 - Extracting MFCCs with Python/Extracting MFCCs.ipynb diff --git a/8- Implementing the amplitude envelope/audio/debussy.wav b/20 - Extracting MFCCs with Python/audio/debussy.wav similarity index 100% rename from 8- Implementing the amplitude envelope/audio/debussy.wav rename to 20 - Extracting MFCCs with Python/audio/debussy.wav diff --git a/23- Spectral centroid and bandwidth/Spectral centroid and bandwidth.ipynb b/23 - Spectral centroid and bandwidth/Spectral centroid and bandwidth.ipynb similarity index 100% rename from 23- Spectral centroid and bandwidth/Spectral centroid and bandwidth.ipynb rename to 23 - Spectral centroid and bandwidth/Spectral centroid and bandwidth.ipynb diff --git a/9- RMS energy and zero-crossing rate/audio/debussy.wav b/23 - Spectral centroid and bandwidth/audio/debussy.wav similarity index 100% rename from 9- RMS energy and zero-crossing rate/audio/debussy.wav rename to 23 - Spectral centroid and bandwidth/audio/debussy.wav diff --git a/9- RMS energy and zero-crossing rate/audio/duke.wav b/23 - Spectral centroid and bandwidth/audio/duke.wav similarity index 100% rename from 9- RMS energy and zero-crossing rate/audio/duke.wav rename to 23 - Spectral centroid and bandwidth/audio/duke.wav diff --git a/9- RMS energy and zero-crossing rate/audio/redhot.wav b/23 - Spectral centroid and bandwidth/audio/redhot.wav similarity index 100% rename from 9- RMS energy and zero-crossing rate/audio/redhot.wav rename to 23 - Spectral centroid and bandwidth/audio/redhot.wav