SOLVED. YA/Kids, Dad is a professional flute player and Mom scared to leave apartment [s]

[Darcy]

Only child female protagonist. Her father is a professional flute player and travels much of the time. Her mother will not leave the apartment. I believe it might be set in New York. I think it ends with the mom coming out of the apartment to find the daughter. There may have been a character named Ursa or Ursula...
I read the book in the 80s or early 90s. Any ideas?

[Cheryl]

It sounds a little bit like something Norma Klein might have written, but I can't guess which.

At least I've given you a free bump!

[Amanda]

I remember this book, the daughter pretends to be missing to get her mom to come out. The daughter's best friend is a boy her own age, if I remember correctly. Hmmm...

[Diana]

Is it The Law of Gravity by Johanna Hurwitz?

[Diana]

This review mentions her dad being a flutist so I'm guessing this is the one.

[Amanda]

I read it under its other title "What Goes Up Must Come Down" -- definitely the book I was thinking of, curious to see if it's Darcy's book :)

[Darcy]

This is it! Thanks everyone! Amanda, I also read it under the title What Goes Up Must Come Down. Book mystery solved!

[Rainbowheart]

What Goes Up Must Come Down for the link.