Automated Piano Playing with Python: Simulating Keyboard Input and Multithreaded Melody Control

The author describes a personal project to help a friend fulfill a piano‑playing dream by writing a Python script that can automatically play piano pieces without any real piano skills.

Effect demonstration – an animated GIF shows the final result of the script playing on an online piano.

Implementation steps – the solution is broken down into four main tasks:

Implement a play function that simulates key presses and timing for each note.

Add separate threads for melody, chords, and individual fingers to achieve a two‑hand effect.

Define the musical score, specifying main melody, chords, and finger assignments.

Automatically open the autopiano web page and send keyboard events to trigger the simulated performance.

Play function code

<code>def play_piano(music, keytime):
    for n in music:
        if n.isupper():
            keyboard.press(Key.shift)
            time.sleep(0.001)
            keyboard.press(n.lower())
            time.sleep(keytime - 0.001)
            keyboard.release(n.lower())
            keyboard.release(Key.shift)
        elif n == "|" or n == ")":
            pass
        elif n in "!@$%^*(":
            keyboard.press(Key.shift)
            time.sleep(0.001)
            keyboard.press("1245689"["!@$%^*(".index(n)])
            time.sleep(keytime - 0.001)
            keyboard.release("1245689"["!@$%^*(".index(n)])
            keyboard.release(Key.shift)
        elif n != " " and n != "-":
            keyboard.press(n)
            if music.index(n) != len(music) - 1 and music[music.index(n) + 1] == ")":
                time.sleep(keytime / 2)
            else:
                time.sleep(keytime)
            keyboard.release(n)
        elif n == "-":
            time.sleep(2 * keytime)
        else:
            time.sleep(keytime)
</code>

Adding melody threads – the script defines strings for right‑hand and left‑hand parts (including thumb and index finger patterns) and launches them with a helper thread_play function to run play_piano concurrently.

<code>right = "s-as f |a --u |p -ops |" \
        "o --uu|i-uis-|u - sss|a-Ii a |" \
        "a --|"
left = "etu --|0wr --|qet --|" \
       "80w --|9qe --|80w --|7Qr --|" \
       "370Wr |"
thread_play(play_piano, 0.3, right, left)
</code>

More complex examples show how to split the score into separate tracks for thumbs and index fingers, adjusting the timing parameter to achieve realistic articulation.

Preparing the performance – the script installs the Chrome driver, launches the autopiano website, and uses webbrowser to open the page.

<code>if __name__ == '__main__':
    keyboard = Controller()
    chromePath = r'C:\Program Files\Google\Chrome\Application\chrome.exe'
    webbrowser.register('chrome', None, webbrowser.BackgroundBrowser(chromePath))
    webbrowser.get('chrome').open('https://www.autopiano.cn', new=1, autoraise=True)
</code>

Finally, the author notes that by modifying the note strings according to any sheet music, the same framework can be used to automate the playback of different piano pieces.