In Dead Again, when Grace is under hypnosis, and telling Dr. Madsen and Mike about when Roman and Margaret Strauss first met, it turns out it was at a concert (Roman was conducting the orchestra, Margaret was playing the piano), and Grace mentions Rachmaninoff was the music being played that night.
In Every Shiny Thing, Lauren remembers Ryan playing piano at last year's Christmas party. Someone asked if he knew any Rachmaninoff concertos, and he answered that his aunts had a Best of Rachmaninoff CD and started playing. This Christmas, Lauren buys him Rachmaninoff sheet music.
Pilgrennon's Children: In Pilgrennon's Beacon, Pilgrennon plays a Rachmaninoff CD in the car during his expedition to get medication for Peter.
In The Young Diana, Diana plays Rachmaninoff's Prélude for Dimitrius and his guests.
