Help needed identifying book

Hi all! Hope you can help me...

I'm remembering a children's / teens book which I'd have read in the late 70s / early 80s. It had a family of children (I think) and one of them finds a little ivory shape, narrower in the middle than at the ends, which is the key to... something. It's not The Indian In The Cupboard and I don't think it's The Ogre Downstairs... but by a writer like Lynne Reid Banks or Diana Wynne Jones.

Help!

The castle of bone by Penelope Farmer?

Ooh, you know it might be... thank you!

I just wanted to say that there's a really great group on LT called Name that Book ( http://www.librarything.com/groups/namethatbook#forums ). Just in case you were ever looking for a book again!

Hi there, I know about that now, I posted the original message almost a year ago. But thanks!

Was the book suggested the one you were looking for?

If not, another possibility might be String in the Harp by Nancy Bond in which siblings find the tuning key for the harp of the Welsh bard Taliesen

I'm pretty sure it's the Castle of Bone, sorry I didn't make that clearer! now to find a copy...

A string in the harp is a great book though, very worth reading if you like Susan Cooper's Dark is Rising sequence. I'd never heard of it till I moved to America, but if I'd found it as a child I think I'd have reread it often.

Hope you enjoy rereading Castle of Bone if you track down a copy!