私はピアノを弾きます！

I agree with Mero's answer. However, I'd like to add a bit more. You have to take care of the translation of "play the (intruments)", we changed them depending on the instruments, for example, play the piano/guitar = ひきます, play the fruit/trampet/saxophone, etc = ふきます, play the drums = たたきます. I hope this helps you.