Simplify the following text for a Grade 10 native English-speaking person.
Original: John Dunstaple or Dunstable ( born about 1390 ; died 24 December 1453 ) was an English composer who lived in the last part of the medieval era and the early part of the Renaissance .
Simplified: John Dunstaple ( or Dunstable ) ( c. 1390 â `` 24 December 1453 ) was an English composer of polyphonic music of the late medieval era and early Renaissance .