The heart follows its own tune in a Regency romance from an author with "considerably more wit and pizazz than the legendary Georgette [Heyer] herself" (Kirkus Reviews).   When Daphne left her family's country estate at Verchamp Park for a season in London, it was certainly with no expectation of romance. She soon discovers, however, that she has no difficulty in finding suitors--only in choosing among them.   All of them are quite acceptable, with the sole exception of Christian Livingston, the handsome and sensuous pianofortist. Surely, little good could come of any attachment she might form for him. And yet, could propriety stand in Daphne's way once her heart has been ensnared?