If you have heard of a shrub called Bridal Veil or Bridal Wreath, this is the one you are looking for.  The Spirea - Renaissance Sp. vanhouttei 'Renaissance'  have arching branches with dark green leaves and delicate white cascading flowers.  As a child growing up in Omaha, Nebraska, I remember seeing them everywhere.  I have always loved their look.  I heard that old-timers wore them as wreaths to their weddings.  In fact, the Greek name 'speria' means wreath.  You could see them on the farm, in the city and in the parks.  They are so easy to care for and very hardy.  I don't remember my parents doing anything with them but letting them grow each year.  I doubt they were ever pruned and yet they continued to put on their display.  I'm sure that pruning is a good idea, however, and would give you more flowering. 

This is a descendant of the old time parent that I probably saw but is so similar that they are hard to tell apart.  These flowers are wonderful in vases or to make into wreaths.  This shrub is also disease resistant.  They make great border shrubs and are considered fountain or vase shaped.  Their fall color is orange-red.  Butterflies are attracted to them and their bright colors would show up beautifully against the white flowers.  You should try one and enjoy the beauty and the butterflies!