How to Create an Interactive Onscreen GUI Piano in Python

Have you ever played a musical instrument before? And if so, have you ever thought of creating a GUI Piano using Python before? Let’s create a GUI Piano using Python together. For that, we need to understand a few things, but at the end of the article, I assure you will create your own working Python piano player.

Creating a Graphical User Interface (GUI) piano using Python can be a fun project for anyone interested in music and programming. In this blog, we'll go through the general steps involved and the implementation of creating a GUI piano with Python.

The first step is to choose a GUI framework to work with. There are several options available, including PyQt, Tkinter, and wxPython. Once you've chosen a framework, you can start building the piano's interface, in which we will be choosing Tkinter.

The piano's interface will typically consist of two main components: the keyboard and the sound engine. The keyboard is usually a set of buttons or keys that can be pressed to produce different sounds, while the sound engine generates the actual sounds in which we need to give different frequencies to generate particular sound

The sound engine is responsible for generating the actual sounds when the keys are pressed. Several libraries are available for working with sound in Python, including PortAudio.

When building a GUI piano, there are a few important things to remember. First, you'll need to ensure the interface is intuitive and easy to use. The keyboard should be easy to navigate, and the sound engine should respond quickly to user input.

You'll also need to pay attention to performance issues, especially when it comes to generating sounds in real time. Depending on the complexity of the sound engine, you may need to optimize your code to ensure that it runs smoothly.

Let’s Implement the Code for GUI Piano in Python

This code defines a simple GUI piano that can be played using the computer's keyboard. It uses the tkinter module to create the GUI, the sound device module to generate sounds, and the numpy module to work with numerical data. For this, we need to install a few Python piano libraries used for developing virtual pianos those are sounddevice, numpy, xvfb, and portaudio19-dev. Let’s understand each one of them in detail

1. tkinter:
   Tkinter is a Python library used for building GUI (Graphical User Interface) applications. It provides a set of tools and widgets for creating desktop applications with a graphical interface. Tkinter is included with standard Python distributions, so it is easy to get started with. It uses the Tk GUI toolkit, which is cross-platform and has been widely used for many years.
2. Sounddevice:
   Sounddevice is a Python library that provides an easy-to-use interface to play and record sound using Python. It uses the PortAudio library for its underlying audio I/O operations and provides a simple way to work with sound streams in real-time or other words virtual player to play sound of notes.
3. Xvfb:
   Xvfb stands for "X virtual framebuffer." It is a virtual display server that allows you to run graphical applications on a headless server (i.e., a server without a physical display). Xvfb provides a virtual framebuffer, which simulates a real display with a size you specify but doesn't show anything on an actual screen.
   Xvfb is useful for a variety of purposes, such as testing graphical applications, running a GUI-based application on a remote server, or creating screenshots or screen recordings of applications running on a server without a physical display.

pip install pyvirtualdisplay
pip install sounddevice
pip install numpy
apt-get install -y xvfb
apt-get install -y portaudio19-dev

import tkinter as tk
import numpy as np
import sounddevice as sd

First, the code defines a dictionary called notes_freq that maps each note name (e.g., "C4") to its corresponding frequency in Hertz. It then creates a tkinter window called root with the title "GUI Piano".

# Define the frequency of each note
notes_freq = {
    "C4": 261.63,
    "D4": 293.66,
    "E4": 329.63,
    "F4": 349.23,
    "G4": 392.00,
    "A4": 440.00,
    "B4": 493.88,
    "C5": 523.25
}

Next, the code defines a list called piano_keys that contains tkinter Button objects for each note in notes_freq. It uses a for loop to create the buttons, sets their text to the note name, and adds them to the window using the pack() method.

# Define the GUI window
root = tk.Tk()
root.title("GUI Piano")

# Define the piano keys
piano_keys = []
for note in notes_freq:
    key = tk.Button(root, text=note, width=5, height=10, bg='black', fg='white', font=("arial", 18, "bold"))
    key.pack(side=tk.LEFT, padx=2, pady=2)
    piano_keys.append(key)

The code then defines a function called play_note that generates a sine wave of the appropriate frequency for a given note and plays it using the sounddevice module. The function takes a note name as its input and uses the notes_freq dictionary to look up the corresponding frequency.

# Define the function that plays a note when a key is pressed
def play_note(note):
    duration = 1  # seconds
    volume = 0.5  # between 0 and 1
    samples = np.arange(duration * 44100) / 44100
    waveform = np.sin(2 * np.pi * notes_freq[note] * samples)
    sd.play(volume * waveform, samplerate=44100)

The code then uses the configure() method of each Button object to bind it to its corresponding note and the play_note function. It does this by passing a lambda function that calls play_note with the appropriate note name.

# Bind each key to its corresponding note and function
piano_keys[0].configure(command=lambda: play_note("C4"))
piano_keys[1].configure(command=lambda: play_note("D4"))
piano_keys[2].configure(command=lambda: play_note("E4"))
piano_keys[3].configure(command=lambda: play_note("F4"))
piano_keys[4].configure(command=lambda: play_note("G4"))
piano_keys[5].configure(command=lambda: play_note("A4"))
piano_keys[6].configure(command=lambda: play_note("B4"))
piano_keys[7].configure(command=lambda: play_note("C5"))

# Run the GUI loop
root.mainloop()

Finally, the code enters the tkinter mainloop using the root.mainloop() method, which waits for user input and updates the GUI as needed.

When the user presses a piano key on the GUI, the corresponding note is played using the play_note function and the sounddevice module. The duration and volume of the note are fixed in this example but could be adjusted as needed.

Output of the above Python piano code

Conclusion

In conclusion, building a GUI piano using Python can be a fun and rewarding project. While there are several steps involved, with the right tools and approach, you can create a functional and enjoyable piano that can be played on your computer.

Interview Questions

1. What is the purpose of the play_note function in the Python code?

Answer: The play_note function generates a sine wave of the appropriate frequency for a given note and plays it using the sounddevice module.

2. How does the Python code bind each key to its corresponding note and the play_note function?

Answer: The Python code uses the configure() method of each Button object to bind it to its corresponding note and the play_note function by passing a lambda function that calls play_note with the appropriate note name.

3. What is Tkinter?

Answer: A Tkinter is a Python library used for building GUI (Graphical User Interface) applications. It provides a set of tools and widgets for creating desktop applications with a graphical interface.

Quiz

1. What is the purpose of the play_note function in the code?

A. To create a tkinter window called root with the title "GUI Piano"

B. To generate a sine wave of the appropriate frequency for a given note and play it using the sounddevice module

C. To define the frequency of each note in Hertz

D. To bind each key to its corresponding note and the play_note function
Answer: B

2. What is the purpose of the code defining a dictionary called notes_freq?

A. To define the frequency of each note in Hertz

B. To create a list of tkinter Button objects for each note in notes_freq

C. To generate a sine wave of the appropriate frequency for a given note and play it using the sounddevice module

D. To bind each key to its corresponding note and the play_note function
Answer: A

3. Which module is used in the code to create the GUI?

A. Numpy

B. Sounddevice

C. Tkinter

D. Pyvirtualdisplay
Answer: C

4. What is the purpose of the xvfb library in the code?

A. To simulate a real display with a size specified

B. To test graphical applications

C. To create screenshots or screen recordings of applications running on a server

D. To run graphical applications on a headless server
Answer: D

5. Why is it essential to pay attention to performance issues when building a GUI piano?

A. To ensure the interface is intuitive and easy to use

B. To optimize the code to ensure it runs smoothly

C. To ensure the sound engine responds quickly to user input

D. To ensure that the keyboard is easy to navigate
Answer: B

Did you know that the average salary of a Python Web Developer ranges between 4 to 9 Lakhs per annum? So it's never too late to explore new things in life, especially if you're interested in pursuing a career as a Python Web Developer. Click here to learn more: Click here to kickstart your career as a data scientist .