“The world’s first typeface you can hear and play” sounds (heh) interesting. Per DesignTaxi,

Visualizing the brilliance of Amadeus Mozart, branding agency Happy People Project has created a typeface to front communications for Peter Shaffer’s play, Amadeus, in Turkey. […]

14 numbers and letters were created in line with notes and octaves on the staff, so you could listen to them. In total, though, a massive font family of 574 characters was designed for the project.

Check it out: