import urllib
urllib.urlretrieve('https://ccrma.stanford.edu/workshops/mir2014/audio/simpleLoop.wav', filename='simpleLoop.wav')

%ls *.wav

from essentia.standard import MonoLoader
audio = MonoLoader(filename='simpleLoop.wav')()
audio.shape

N = len(audio)
t = arange(0, N)/44100.0
plot(t, audio)
xlabel('Time (seconds)')

import librosa
x, fs = librosa.load('simpleLoop.wav')
print x.shape
print fs

from IPython.display import Audio
Audio('https://ccrma.stanford.edu/workshops/mir2014/audio/CongaGroove-mono.wav') # remote WAV file

Audio('simpleLoop.wav')  # local WAV file

fs = 44100 # sampling frequency
T = 1.5    # seconds
t = numpy.linspace(0, T, int(T*fs), endpoint=False) # time variable
x = numpy.sin(2*numpy.pi*440*t)                # pure sine wave at 440 Hz
Audio(x, rate=fs)

T = 0.001    # seconds
fs = 44100   # sampling frequency
t = numpy.linspace(0, T, int(T*fs), endpoint=False) # time variable
x = numpy.sin(2*numpy.pi*3000*t)     
plot(t, x)
xlabel('Time (seconds)')

S, freqs, bins, im = specgram(x, NFFT=1024, Fs=fs, noverlap=512)
xlabel('Time')
ylabel('Frequency')

from essentia.standard import MonoWriter
noise = 0.1*randn(44100)
MonoWriter(filename='noise1.wav')(single(noise))
%ls *.wav

import librosa
noise = 0.1*randn(44100)
librosa.output.write_wav('noise2.wav', noise, 44100)
%ls *.wav