Musicians know the person in the background is sometimes holding the entire structure together. The drummer who never overplays but somehow defines the feel of the track. The arranger who shapes the architecture so subtly you think the song was born that way. Jim Keltner or Fletcher Henderson. There are players like that in film too. That is how I perceived Robert Duvall. Standing in the corner making it real. When I heard he died what struck me was the cumulative weight of all the subtle ones. The musician who plays the right note instead of the impressive one. No surprise he could inhabit a singer songwriter so well in Tender Mercies. Great players understand music is about supporting the song. Duvall carried that in the film serving the story. Master of background gravity.