Analog audio mixer controllable via MAX/MSP

I'm wondering if the following would be possible using Arduino, and if so, what hardware would be required:

Analog audio mixer controllable via MAX/MSP

—ideally would be a matrix mixer (say 4 in and 4 out) where any combination of inputs could be sent to any combination of outputs

—ideally these sends would have gain control or passive attenuation. Simple on/off would be OK too.

— alternatively one-channel active or passive gain controls or on/off gates would work.

The purpose is to automate with Max a 'no input' analog feedback systems using guitar effects pedals.

Any pointers much appreciated!

Thanks for your reply! I found the following chips that look useful-- just wondering what Arduino hardware would be necessary for the project:

3 X 3in/2out
http://www.maxim-ic.com/datasheet/index.mvp/id/2046

mic preamp
http://www.maxim-ic.com/datasheet/index.mvp/id/3406

Just use the SPI library to talk to this one, very simple connection.
3-Wire SPI/QSPI/MICROWIRE-Compatible (MAX4549)

The second one, looks like you need a logic signal to switch between the two inputs.
Can be arduiono driven directly, or the output of a register that the ardiuno writes to.