Between Each Breath — Adam Thorpe

Jack Middleton, once 'England's most promising young composer' now lives comfortably in Hampstead with his wife Milly, an heiress. Jack is no longer young nor has he ever quite fulfilled his remarkable promise. And then he visits Estonia, in search of inspiration, and falls for a young waitress, Kaja. Six childless years on and Jack and Milly's marriage shows the strain, but they battle on better than most - until the past returns with a vengeance...