New to Pd, and I am doing an independent study this semester entitled Pure Data for Performance. My aim for the end of the semester is create a patch with pd and GEM that will allow for a loop based musical performance with synched graphical rendering in GEM.

But, first thing is first. How would I route the audio output from Ableton live to pd to provide the loops(triggered via a midi controller) or would it be easier to somehow just trigger the loops through Pd? I read about using an IAC bus but couldn't figure it out. Any advice=great appreciation.

-Evan_

you can use jack to route the audio signal to PD.

i've heard "soundflower" mentioned before in this context (routing audio between apps on OS X) - not sure if commercial apps support Jack

I'm only working with the mac so some of these things will be different on other platforms:
In essence jack and soundflower are doing the same thing. They create virtual audio connections between applications. You could make a new virtual audio connection between live and pd. You need to route Live's audio out to jack or soundflower. In pure data you will be able to select an audio in (source) from the Jack or soundflower application (instead of your normal audio in like your soundcard and core audio).
I used both some years ago and they worked perfectly. I would start with checking leopard compatibility when choosing between the applications.

IAC is used for making a virtual midi channel. You make a new virtual midi channel and connect them with the new channel. The IAC thing works pretty good. If you trigger the signals in pd you can make a midi mapping in ableton live. Pretty straightforward and very flexible. The IAC thing can be found under applications/utilities/audio midi setup.

Edit: I just started reading your post again. Why not dropping live at all? You can easily read the messages from your external controller in pd.

i will investigate those two programs. And I don't know about triggering samples via Pd. I am already comfortable performing with Live. My vision is to use Pd as a means to communicate the data to Gem.
For example, when i trigger a particulare loop, it would also trigger some rendering in GEM, and I would link the sliders and rotary encoders that control parameters in live to control parameters in GEM.

Is this realistic?... I am just starting but by next week I will have some more answers as to linking GEM and my midi control.

Thanks for the prompt responses by the way. You guys are great

(edit) So, I downloaded soundflower and was able to select it for the out from ableton and the in for Pd. What next?

-Evan_

use [fiddle~] to measure the audio signal form ableton.
you can open the help of the [fiddle~] to learn how to use it.
and you should read the basic tutorial in pd, i think you know it.