What instruments are used in the recent "Sherlock Holmes" soundtrack?

I just saw “Sherlock Holmes” (with Robert Downey, Jr. and Jude Law) and loved it. The soundtrack was perfect, beautiful but just dark and demented enough to fit the era.

I know there are strings and piano, but it was another instrument, sometimes used solo, that is stuck in my head. It sounded like a violin combined with a piano—autoharp maybe?