title: Musical notation
context: The earliest form of musical notation can be found in a cuneiform tablet that was created at Nippur, in Sumer (today's Iraq), in about 1400 BC. The tablet represents fragmentary instructions for performing music, that the music was composed in harmonies of thirds, and that it was written using a diatonic scale.[2] A tablet from about 1250 BC shows a more developed form of notation.[3] Although the interpretation of the notation system is still controversial, it is clear that the notation indicates the names of strings on a lyre, the tuning of which is described in other tablets.[4] Although they are fragmentary, these tablets represent the earliest notated melodies found anywhere in the world.[5]
question: When was written music first developed?
answers: 1400 BC