Game doesn't recognize my playing
1) Your background music could be too loud. If you are using speakers, make sure that those are not too loud. Alternatively you can use headphones.
2) Turn off any effects on your keyboard. Any effect will affect the recognition, please use as clear signal as you can to get the best recognition.
3) You microphone input could be too low. Please check that your microphone input is high enough. You can see how to do it from these link:
4) Make sure your instrument is calibrated in app in the calibration screen located at the start of every song.
Please also check this article about setting up your piano or keyboard instrument.