Where did my prior instrments go????

I have quite a few songs I created on the prior version, I loved it.
I naturally thought this new upgrade would preserve my instruments (especially the synths).
They have all now defaulted to flute-like sounds. Even after downloading the optional 5Gb add-on.
What do I do to get my songs back????
My first Bad Apple!

Slats66 about GarageBand, v10.0.3