I would have seen this movie in the 70's, but not sure the year it was made. All I remember is a lady at the top of the stairs, looking down, and only hands playing the piano. Does anyone remember the title?

It most likely was The Beast With Five Fingers (http://en.wikipedia.org/wiki/The_Beast_with_Five_Fingers). The hand belonged to a pianist. Less likely match is The Crawling Hand (http://www.imdb.com/title/tt0056961/); I don't think that one involved a piano, though. :)