Auto-Tune is a software tool used in music production to correct pitch in vocal performances. It helps singers sound more in tune by adjusting their notes to the nearest correct pitch. This technology can make a performance sound polished and professional, even if the singer isn't perfect. Originally developed in the late 1990s, Auto-Tune has become a popular effect in many music genres, especially in pop and hip-hop. Some artists, like T-Pain, have even embraced its unique sound, using it creatively to enhance their music. Overall, Auto-Tune has changed how we hear and produce music today.