Question

i need to do piano in matlab . its keys number should ve 88 and i need a source . Can u help ne ?

Answer 1

From the existing piano, we have determined frequencies of each and every key. We have assigned those
frequencies to virtual keyboard. And we also studied that, how to simulate the graph of each frequency tone by using graphical user interface (GUI).
A graphical user interface (GUI) is a user interface erected with graphical objects, such as push buttons,
radio buttons, axes, text fields, sliders, and menus. In general, these objects already have significance to most
computer users. For example, when you move a slider on the layout editor of GUI, a value changes; when you
press an OK button, your settings are enforced and the dialog box is ousted. Of course, to influence this built-in
intimacy, you must be persistent in how you use the distinct GUI-building components. Applications that support
GUIs are generally simple to learn and use since the person using the application does not need to perceive what
commands are feasible or how they work. The action that results from a specific user action can be made clear by
the design of the interface. The sections that follow illustrate how to create MATLAB GUIs. This consists of
laying out the components, programming them to do specific things in response to user actions, and saving and
launching the GUIs.
The process of implementing a GUI involves two basic tasks:

• Laying out the GUI components
• Programming the GUI components GUIDE chiefly is intent of layout tools. However, GUIDE also produces

An M-file that includes code to handle the initialization and launching of the GUI. This M-file supports a
framework for the implementation of the callbacks (the functions that execute when users activate components
in the GUI). The application of a GUI, While it is possible to write an M-file that includes all the commands
to lay out a GUI, it is simple to use GUIDE to layout the components commonly and to produce two files that
save and launch the GUI:

M-file: includes the functions that dispatch and control the GUI and also the callbacks which are defined as sub
functions. This M-file is referred to as the application M-file in this documentation.

• Piano key frequencies:

This is a list of the complete frequencies in hertz (cycles per second) of the keys of a modern 88-keys standard
or 102-keys piano in 12 -tone equal temperament, with the 49th key as the center and fixed with 440 Hz (referred
to as A440). Each subsequent pitch is derived by multiplying (ascending) to the left or dividing (descending) to
the right previous by the twelfth root of two (approximately 1.0594631...). This deviation from equal temperament
is called the Railsback curve.
The following equation gives the frequency f of the n
th key, as shown in the table:
f (n) = (12√2)n-49x 440Hz
(a' = A4 = A440 is the 49th key on the idealized piano)
Alternatively, this can be written as:
f(n) = 2n-49/12 x 440Hz
Conversely, starting from a frequency on the idealized piano tuned to A440, one obtains the key number by:
n = 12log2 (f/440Hz) + 49