Have just been to see the film Shutter Island and Leonardo Di Caprio makes a point of identifying a piece of music as Mahler Quartet for Piano and Strings. I initially thought he was mad. "Mahler only wrote symphonies and song cycles" I pompously told my friend. "It's Scorsese's clever way of hinting at Di Caprio's state of mind". I was wrong. It appears Mahler did write it. Does anyone have any information on it please? The Penguin and Gramophone Guides do not list it. Is it a good piece and worth seeking out? Appreciate any pointers.