logic's sound with mpc

[creativpop]

I want to make it as simple as possible....

 

ok my mpc is coonected to a firebox and that to speakers ETC.

 

I have my midi keyboard (midi)Axiom 25// no sounds in it....connected directly in to a MAC Book PRo.. via USB.

 

Ive already got samples / drums etc in the mpc ...

 

So heres the problem lets say i just finished playing 8 bar drum loop within the mpc 1000.

 

now i want to add strings chords or whatever how can i do this in real time like the drums are still playing

 

and then using the midi keys to access logics pianos with them being recorded in to the MPC 1000.

 

any help .....