THe Projects are all upwards compatible:
GarageBand iPad: can be opened in GarageBand11, GarageBand X, LogicX
GarageBand11: can be opened in,GarageBand X, LogicX
GarageBand X: can be opened in LogicX
Here is a screenshot (from my new GarageBandX book) about Apple's ecosystem, how the apps are connected
Hope that helps
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