I think
Philomela is a darling name, and while the mythical story is rather grisly, I like the fact the mythical heroine was turned into a nightingale. Since
Pip can be a nickname for
Philip, would it be a stretch if it could be short for
Philomela? From the ones you listed, my favourite combos are:
Philomela ClarePhilomela DaphnePhilomela HazelPhilomela HelenPhilomela RachelPhilomela Sophie