Most of us have a music player when we travel these days. I'm listing what is supposed to be Agatha Christie's favourite music, which she might have on an I-Pod if she were travelling in 2010.
Sibelius: Symphony No. 1 in E minor, Op. 39
Wagner: Ride of the Valkyries
Elgar: Enigma Variations
Elgar: Cello Concerto in E Minor (Opus 85)