There are a number of ways to use a MIDI controller in Ableton Live. This article will cover how to make sure your MIDI controller is set up properly, get you started on how to use your controller as a control surface, and illustrate how to configure basic mappings.

Basic Setup

The most common use for MIDI controllers in Live is to input note information. To set your controller up for this, take the following steps:

1. Connect your MIDI controller to your computer and make sure it is turned on.
2. Open Ableton Live.
3. Open your Ableton Live Preferences (referred to as Settings in some versions of Live).
4. Navigate to the Link Tempo MIDI tab of the Preferences menu.
5. Find your controller in the MIDI Ports section of the Link Tempo MIDI tab. There will be listings for the controller preceded by both In and Out.
6. On the listing for your controller preceded by In, ensure the box in the Track column is checked.

7. Close the Preferences menu.
8. If you don't already have a MIDI track created, create one by selecting Create > Insert MIDI Track.
9. Ensure that either All Ins or your MIDI controller is selected in the MIDI From drop-down menu on your MIDI track.

10. Record-enable the MIDI track by clicking the record-enable button on the track, as shown below. The button will turn red when the track is record-enabled.

You should now be able to record note information on that track. Note, in order to hear any sound from the track, you'll also want to instantiate a virtual instrument on the track. The easiest way to do this is to select the track by clicking on its name, navigate to the virtual instrument you want to use in Live's browser, then double-click on the instrument.

Using Your Controller as a Control Surface

Using your controller as a control surface is a great way to take advantage of auto-mapped functions, which might allow you to control various parameters or launch clips from your controller. If your controller wasn't specifically made for use with Ableton, you may need to take additional steps, either on your controller or within your controller's software, to have it properly function as a control surface. Consult your controller's manual if it is still not functioning as expected after taking the steps listed below. Controllers such as the Ableton Push or Akai APC 40 mkii are examples of controllers that will have full control-surface functionality without any additional steps.

To set up your controller as a control surface, take the following steps:

1. Connect your MIDI controller to your computer and make sure it is turned on.
2. Open Ableton Live.
3. Open your Ableton Live Preferences (referred to as Settings in some versions of Live).
4. Navigate to the Link Tempo MIDI tab of the Preferences menu.
5. In the Control Surfaces column under the MIDI section, select your controller. If using a controller designed specifically for Live, like the Push or APC 40, this should automatically populate (along with the Input and Output columns). Note: You can configure up to six control surfaces at once, so if you already have another one set up, use an empty line. 
6. In the Input and Output columns on the same line, select your controller. If you are using a Push and these columns are not populated automatically, select Ableton Push (Live Port) in both columns, rather than Ableton Push (User Port).

Mapping Your Controller to Control Other MIDI Functions

You may want to use your controller to do more than just input notes. Some examples include controlling volume on a track, a filter's cutoff frequency, track panning, or launching clips from the Session view. You can configure your controller to do almost anything that you can do with the mouse in Ableton Live's graphical user interface, with some exceptions. To do that, take the following steps:

1. Connect your MIDI controller to your computer and make sure it is turned on.
2. Open Ableton Live.
3. Open your Ableton Live Preferences (referred to as Settings in some versions of Live).
4. Navigate to the Link Tempo MIDI tab of the Preferences menu.
5. Find your controller in the MIDI Ports section of the Link Tempo MIDI tab. There will be listings for the controller preceded by both In and Out.
6. On the listing for your controller preceded by In, ensure the box in the Remote column is checked.
7. Close the Preferences menu.
8. Click the MIDI button near the top right corner of Live to enter MIDI Map mode. After doing that, a number of the elements on the screen will be highlighted in blue—these are elements that you can map to a key/knob/fader/pad on your controller. You may also notice a few options that aren't available when just using the mouse, such as Scene Up, Scene Down, Cancel Scene Launch, etc.

9. Click the onscreen element that you want to control from your controller, then press the key (or move the fader, turn the knob, etc.) you want to use to control that function.
10. Repeat step 9 for as many functions as you want to map. You may notice that each time you map a function, it will appear in the Browser on the left hand side of the screen. In the Browser, you can see in the CC or note value controlling the function, as well as adjust the range the element is controlling.
11. Click the MIDI button again to leave MIDI Map Mode.

You should now be able to control the function(s) that you mapped in Step 9 by using the appropriate key/fader/knob/pad on your controller.