The Constant Nymph (Virago Modern Classics) - Kennedy, Margaret

Avant-garde composer Albert Sanger lives in a ramshackle chalet in the Swiss Alps, surrounded by his 'Circus' of assorted children, admirers and a slatternly mistress. The family and their home life may be chaotic, but visitors fall into an enchantment, and the claims of respectable life or upbringing fall away.
When Sanger dies, his Circus must break up and each find a more conventional way of life. But fourteen-year-old Teresa is already deeply in love: for her, the outside world holds nothing but tragedy.