Problem with .get() in tkinter, how do i get my second and third song to play?

Hey so im a new programmer and i wanted to know why when i choose the second option in the music_list, it doesnt play the second song, instead it plays nothing. It works for valley but not for Night sky or crossing cat

            if (self.time_left <= 0) and (self.mus_combobox.get()=='Valley'):
                process = multiprocessing.Process(target=playsound, 
                args=('Valley.mp3',))
                process.start()
                messagebox.showinfo("Time's Up!","TIME'S UP!")
                process.terminate()
                # Clearing the 'self.button_frame' frame
                self.Clear_Screen()
            if (self.time_left <= 0) and (self.mus_combobox.get()== "Night Sky"):
                process = multiprocessing.Process(target=playsound, 
                args=('Night.mp3'))
                process.start()
                process.terminate()
                messagebox.showinfo("Time's Up!","TIME'S UP!")
                self.Clear_Screen()
            if (self.time_left <= 0) and (self.mus_combobox.get()== "Crossing cat"):
                process = multiprocessing.Process(target=playsound, 
                args=('Nightsky.mp3'))
                process.start()
                process.terminate()
                messagebox.showinfo("Time's Up!","TIME'S UP!")
                self.Clear_Screen()

self.mus_combobox is the list that contains all the music names

    
    def musicplay(self):
        self.mus=IntVar()
        self.mus_combobox= ttk.Combobox(self.window, width=9,
        height=10, textvariable=self.mus,
        font=("times new roman",8))
        self.mus_combobox['state']='readonly'
        self.mus_combobox['values']= music_list
        self.mus_combobox.current(0)
        self.mus_combobox.place(x=320, y=370)