AudioKit Synth One - Free & Open-source iPhone/iPad Synth 🎹
Clone Hero - Clone Hero is a free rhythm game, which can be played with any 5 or 6 button guitar controller...
Sampulator - Make (and record) beats on your keyboard
Frets on Fire - Bonus content.
Logic Pro X - Music production.
Osu - Osu is Music, Rhythm, Single and Multiplayer video game developed by Dean Herbert.