You can change the key of the song with the Transpose feature .
This helps if you find that a song is too high or too low for you to comfortably sing, You can access it from the Pause menu, by tapping anywhere on the screen in Practice and Play mode.
Use the Auto transpose option if you have previously calibrated for your vocal range. You can also use the + and - buttons to manually transpose the song.
Next up: Best way to practice