We start as usual by building the root window (7.01/view.py):

root = Tk()
SCREEN_WIDTH = root.winfo_screenwidth()
SCREEN_HEIGHT = root.winfo_screenheight()
SCREEN_X_CENTER = (SCREEN_WIDTH - WINDOW_WIDTH) / 2
SCREEN_Y_CENTER = (SCREEN_HEIGHT - WINDOW_HEIGHT) / 2
root.geometry('%dx%d+%d+%d' % (WINDOW_WIDTH, WINDOW_HEIGHT, SCREEN_X_CENTER,  SCREEN_Y_CENTER))
root.resizable(False, False)
PianoTutor(root)
root.mainloop()

We also create a new file named constants.py( 7.01), which currently holds the height parameters for the window.

We use two root window methods,  root.winfo_screenwidth()and root_winfo_screenheight(), to obtain the screen width and height, respectively. We define two constants,  WINDOW_WIDTH and WINDOW_HEIGHT, and then place the window on the x, y center of the computer screen.

Notice the line root.resizable(False, False). This root window method takes two Boolean arguments to decide if the window is resizable in the x and y directions.  Setting both arguments to False makes our window fixed in size. 

The root window is then passed as an argument to a new class, PianoTutor, which takes care of building the internals of the program. This class is defined next.

The GUI for this program is divided into four broad rows:

The topmost row is built in a Frame named mode_selector_frame and has a combobox that lets the user select from one of three options—scales, chords, and chord progressions.

The second row is a placeholder for placing the music score sheet and is accordingly called the score_sheet_frame.

The third row requires a bit of attention. Depending on what is selected in the topmost combobox, the contents of this row change.  In our code so far, (7.01/view.py), it displays three different colored frames for the three different choices one can make using the topmost combobox. Since we will place controls on this frame, we decided to call it a controls_frame for want of a better name.

The fourth row shows the piano keyboard and the frame is named keyboard_frame, the implementation of which will be discussed in the section entitled Making the Piano Keyboard.