BDH produced a series of films to accompany the performace of Vivaldi’s Four Seasons by the Emerald Ensemble.

This is the Largo from Concerto No. 1 in E major, Op. 8, RV </wiki/Ryom_Verzeichnis> 269, “La primavera” (Spring).

Vivaldi wrote sonnets for each concerto in the Four Seasons. For this piece he wrote:

“And now, in the pleasant, flowery meadow, to the soft murmur of leaves and plants, the goatherd sleeps with his faithful dog at his side.”

Each musical element clearly illustrates this scene and the shapes in the animation aims to reflect that.

http://www.emeraldensemble.co.uk/

this links is about the piece in general

http://classicalmusic.about.com/od/baroqueperiod/ss/fourseasons.htm