harmonizer.py

import curses, os

def main(stdscr):
    # do not wait for input when calling getch
    stdscr.nodelay(1)
    while True:
        # get keyboard input, returns -1 if none available
        c = stdscr.getch()
        if c != -1:
            # print numeric value
            stdscr.addstr(str(c) + ' ')
            if 47 < c < 60:
            	os.system(f"sox --buffer 2048 -c 1 -r 48000 -t alsa default -t alsa default pitch {(c-48)*100} &> /dev/null")
            else:
	            os.system("pkill sox")
            stdscr.refresh()
            # return curser to start position
            stdscr.move(0, 0)

if __name__ == '__main__':
    curses.wrapper(main)