What he said. Strumming the harp just roll your fingers up the keyboard. It helps if you have waterfall keys, but not necessary.
Or find a harpist to record. For some reason my wife hired one for our girl's birthday party. Twelve 12 year olds crammed into a small living room w/ a very big harp. ;-)
https://soundcloud.com/a-pleasure-dome
http://www.bnoir-film.com/ there came forth little children out of the city, and mocked him, and said unto him, Go up, thou bald head; go up, thou bald head.
24 And he turned back, and looked on them, and cursed them in the name of the Lord. And there came forth two she bears out of the wood, and tare forty and two children of them.