Dunstable, Quam pulcra es
Very little is known about the life of English composer John Dunstable (c. 1390-1453) (sometimes listed as Dunstaple or Dunstapell or Dumstable), yet he is universally acknowledge as one of the most influential composers of the 15th century. His music in some ways signals the end of the Medieval period and the beginning of the Renaissance. Of course, there is no bright line separating the Medieval from the Renaissance, but music historians often use 1450 as a convenient divider.
Dunstable uses harmonies based primarily in thirds. While the development of the Western tonal system will require a few more generations, this marks a clear movement toward tonality and away from the predominance of perfect intervals (4ths and 5ths). The result is that you often tend to hear major harmonies. And the music tends to be homophonic with a clear melody line and supporting voices moving in concert with the melodic voice.
It is generally believed that Dunstable traveled to France and then came into contact with composers of the highly influential Flemish school who adopted some of Dunstable’s techniques and spread them across Europe, one of the few examples of the English being innovators of a continental style.
The motet Quam pulcra es, written c. 1430, takes its text from the Song of Songs. It was a popular text, and you can find later settings by major Renaissance composers like Palestrina, Gombert, and Monteverdi.