4chord MIDI – the USB MIDI keyboard to play every major hit pop song with four little buttons. by Sven Gregori:
4chord MIDI – the USB MIDI keyboard dedicated to play all the four chord songs, from Adele via Green Day and Red Hot Chilli Peppers to U2 and Weezer. Thanks to MIDI, you can be any instrument – and all of them at once. Yay!
4chord MIDI Plays All the Hits – [Link]