This piano movement is known as both "Asturias" and "Leyenda". The Spanish composer Isaac Albeniz included the piece within his "Cantos de España", and after his death a music publisher also added it to the "Suite Española" which has caused some confusion over the years. It is a very evocative piece and was later arranged for classical guitar by Andres Segovia. (Here is a young John Williams playing a guitar arrangement on youtube.) The music has also been used in the UK on television adverts for Scottish Widows.