Planting grasses for height and movement as they do on the makeover programmes

[Nattsalie]

Won't they seed everywhere leaving my beds a mass of grass?

If not, can anyone recommend a suitably attractive swishy grass for me.

The species are those which grow naturally into a tight clump, not those which have long running roots which cause such havoc in flower beds.

Miscanthus sinensis is a cracker
as is arundo donax
and stipa gigantea