This is a page for anyone who gives a crap about MATLAB and music theory, who is keen to see more about how each work. Some of this article will refer to theory that is covered in Digital Signal Processing aka. Most of the things mentioned will be pretty basic though, so don't freak out too hard, because it will be easy for you to find out more about them using:.

For simplicity's sake, this is not intended to be completely correct within the bounds of DSP, so any of my DSP chaps please don't think that I believe everything I am saying. I will, at least in the beginning, make some sweeping generalisations and enormous simplifications for the benefit of those people with no DSP experience. Arguably the purest or most beautiful of all the vibrations oscillations is the sine cosine wave.

It should reveal itself to you at some point in your mathematical or electrical career, that all sounds signalscan fairly well be constructed or described by the sum of sine waves of different phase or frequency.

It was Pythagoras the father of music and geometry? People probably already knew about the octave, and the inherent likeness of two notes separated by an octave interval, but it wasn't long before Pythagoras twigged onto the relationship that an "octave" interval in music consisted of a wave in this case and in the case of many instruments, a standing wave on a string oscillating at twice the frequency of the original.

In Western Music there it is tradition to divide the "octave" interval into twelve smaller "equal" intervals semitones. I believe this trend was also started by Pythagoras. It is not the only way. In some Eastern cultures the octave is divided into 24 smaller intervals quartertonesand there are obviously countless ways to do it.

It just so happens that Western music is pretty sweet and easy to work with, so I'll focus on that in this article.

That is, there are no intervals between the notes of the scale that are larger than one whole tone. The "Major Scale" is the most famous of the diatonic scales primarily because it rules. The major scale is easy to locate on a piano by starting on C and playing only the white notes up to the next C.

Not only does the major scale rule pretty hard, it is the basis for all other commonly accepted diatonic scales, the "modes".

The modes basically consist of the Major Scale starting on different tonics notes in the scale. You can see that it has started on what was the second note of the Major Scale, and played up until the octave is reached. You could achieve this on a piano by playing all of the white notes starting from D. Now to the fun part. It is at the basis of music that we find a relationship between pitch and frequency. The following function is very very basic as you can see from the 3 lines of actual non-definition code.

Of course, this function is ONLY so simple because the majority of the work is done by the functions sin and soundsc. Here's an alternate version which allows multiple frequency components for chords, harmonics, etc. For example to create an A major chord you pass the vector [ In the function above, you probably noticed the argument "fs" being thrown around a lot.

Sampling frequency is fundamental in quantising an analogue continuous signal into a digital discrete one. If you want to learn more, I eagerly point you in the direction of wikipedia or any DSP resource. It is important to note that the sampling frequency must be at least twice as large as the frequency given by f1, in accordance with the Nyquist Theorem. Given that humans cannot hear above around 22kHz, it is reasonably safe to use a sampling frequency of 44kHz.

Given that a lot of audio codecs use So a good value for f1 might be Hz. A chord is essentially any sound where there are multiple fundamental frequencies of oscillation.

This definition means we can ignore the harmonics that are naturally present in fairly well every musical instrument but not in MATLAB [yet] where your frequency components are very well defined. This is simply because most people like chords that "sound nice". Chords that sound nice usually have some pretty nifty mathematics behind them!Ryan McGee.

I then played back the octave at different multiples of the sampling frequency and observed the change in pitch. I continued by adding commands to control note duration and produce octave shifts without changing the sampling or reconstruction frequency. Lastly, overtones were added to each note, which I used to play back a short piece of music. Setting the Sampling and Reconstruction Frequency.

First, I chose Fs1 to be 44, Hz, which is the default sampling rate for most computer audio cards when recording music or sound samples. I also chose to hold the reconstruction frequency, Fr, constant at Fs1 and use Fs as the sampling frequency that I modify to produce changes in the sound. Figure 1. Effect of Changing the Sampling Frequency on a Note. The N variable is multiplied by a number in order to produce notes of a reasonable length in time when output to speakers.

By modifying the multiplier one can effectively change the tempo of the output notes. The array, n, is a function that takes the argument, L, which scales the length of the array to result in longer or shorter note duration. L is set to 1 by default so that there is no duration change. Generation of Sinusoids. I then added an octave shift function to downsample or upsample respectively.

Notice that the note function takes a third argument, fN, that will determine which musical note is generated by the sinusoid.

We see that the sinusoid is construced as in the following pseudocode:.

## create a piece of music using matlab??

The oct and n functions become very useful when creating music because the composer can change the octave and duration of each note on the spot without having to create all 88 notes of the standard musical keyboard. Thus, digital keyboards would only need to store 12 sound samples of each preset in their memory to be able to play all 88 notes.

The variable m is the desired octave and input for the oct function which generates the appropriate multiplier to change the octave of a note by downsampling or upsampling. We see that the note will be downsampled if the desired octave is greater than or equal to zero and upsampled if the desired octave is less than zero.

So, to move up one octave we enter 1 for m, which is translated into a 2 by the oct function. To move down one octave we enter -1, which is then translated into 0.

Result: The Note A at Hz. Figure 2. By moving up one octave using downsampling we see twice as many cycles of the A waveform within the same number of samples, which tells us that the output frequency has doubled to Hz. Notice that downsampling has the same effect on the note as changing the sampling frequency. Hence, the advantage of downsampling is that it lets us modify pitch without changing the sampling or reconstruction frequency.

Generation of Musical Notes with Overtones.

### MATLAB For Dummies Cheat Sheet

To produce a more natural sound I added two overtones to each note. Each note is a sum of three instances of the general sinusoid defined earlier.

The first instance is the note played at its standard frequency in the desired octave input by the user. The last two instances are the note played at one octave below and one octave above the input octave. Each instance is multiplied by either namp to set the amplitude of the natural frequency or hamp, which sets the amplitude of the harmonic frequencies.Sign in to comment.

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You are now following this question You will see updates in your activity feed. You may receive emails, depending on your notification preferences. Passband Modulation on 21 Sep Vote 0. Edited: Ryan Black on 16 Apr at Assign the duration of each note as 0. Cancel Copy to Clipboard.

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Sean de Wolski on 21 Sep In grad school I figured out how to play every Linkin Park song:. Answers 7. Star Strider on 21 Sep Vote 4. I suggest:. Can you provide the sequence of Notes for playing Game of Thrones Music. Walter Roberson on 15 Apr Dylan Vizcarra on 24 Nov This is a matlab code that simulate a PV array. Using this code you can have the different caracteristics of a pv array such as I - V and P - V from these characteristics you can observe the values of the short circuit current and the open circuit voltages This project contains the matlab code for GMSK modulation and demodulation of a communication system.

Please check the readme file for more details The source code is written in matlab for the implementation of a music algorithm. Genetic algorithm of computing- matlab code case modeling variable dimensionality Polyphase filters are avoided and replaced by a folding scheme at the receiver level Login Sign up Favorite. Upload Add Code Add Code. Search matlab code music algorithm 2D DOA estimationresult s found. Matlab Matlab. Sponsored links. Latest featured codes. Most Active Users.

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If nothing happens, download GitHub Desktop and try again. If nothing happens, download Xcode and try again. If nothing happens, download the GitHub extension for Visual Studio and try again. These solvers are written as short Matlab scripts and they are now publicly available as I've moved to another field of CFD. All references can be found as comments inside the scripts. Any feed back on these snippets is always welcome. Happy coding! Skip to content. Dismiss Join GitHub today GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together.

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**Audio Signal Processing in MATLAB**

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You are now following this question You will see updates in your activity feed. You may receive emails, depending on your notification preferences. Passband Modulation on 21 Sep Vote 0. Edited: Ryan Black on 16 Apr at Assign the duration of each note as 0. Cancel Copy to Clipboard. Sean de Wolski on 21 Sep In grad school I figured out how to play every Linkin Park song:.

Answers 7. Star Strider on 21 Sep Vote 4. I suggest:. Can you provide the sequence of Notes for playing Game of Thrones Music.Using such a complex environment can prove daunting at first, but this Cheat Sheet can help: Get to know common MATLAB commands; become familiar with common operators and precedence; and learn to recognize line plot styles.

However, these commands are usually used several times each session. Knowing the order in which tasks are performed is essential. Creating a plot that uses differing line types and data point symbols makes the plot much easier for other people to use. The following table contains a listing of the line plot styles. Remember that you can also use these styles with other kinds of plots. For example, a scatter plot can use these styles to define each of the data points.

When in doubt, try the styles to see whether they work with your particular plot. He has produced 96 books and more than articles to date and has been following MATLAB development for nearly a decade.

Cheat Sheet. A true value becomes false and a false value becomes true. Notice that the relational operator uses two equals signs. A mistake many developers make is using just one equals sign, which results in one value being assigned to another.

This operator returns the same value that you provide as input. Operator Description Parentheses are used to group expressions and to override the default precedence so that you can force an operation of lower precedence such as addition to take precedence over an operation of higher precedence such as multiplication.

Negates the truth value of a single operand. Determines whether two values are equal. Provided purely for the sake of completeness. Parentheses are used to group expressions and to override the default precedence so that you can force an operation of lower precedence such as addition to take precedence over an operation of higher precedence such as multiplication.

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