Has anyone done any work with core audio, wrapped any of it for xojo?
Christian, do you have much of the core audio in MBS?
What do you want to do?
Recently I started a new AUPlayerMBS class:
http://www.monkeybreadsoftware.net/class-auplayermbs.shtml
I can send Midi Control Changes with PortMidiMBS
Can I query a Controller Value with PortMidiMBS ?
for example:
I wanna know what value has Controller 18
You can try 
for send I use
Sub SendCC(value2 as integer, value3 as integer)
dim d as PortMidiEventMBS
dim e as integer
d=new PortMidiEventMBS
d.Set (&hB0, value2, value3)
e=s.Write(d)
End Sub
but I couldn’t figure out how I can read it.
you can call Read functions.