French Horn Racer uses the microphone to listen as you quickly switch between notes to keep your car fueled. Pull out your French Horn and play the correct Notes to pass the other cars. How many cars can you pass? The Perfect app for beginners and advanced players of all ages: Works with your REAL instrument. Uses the device's microphone to listen and analyze each note you play. The scoreboard shows you best time, and how many cars you have passed. Unlock new cars based by your performance.