Tracks Menu

• Audio Track — This creates a new empty Audio Track. This command is rarely needed, since importing, recording, and mixing automatically create new tracks as needed. But you can use this to cut or copy data from an existing track and paste it into a blank track. If that track was at a non-default rate then you may need to use Set Rate from the Track Pop-Down menu to set the correct sample rate.
• Stereo Track — same as above, but creates a stereo track. You can also create a stereo track by joining two tracks using the track pop-down menu.
• Label Track — This creates a new Label Track, which can be very useful for textual annotation.
• Time Track — This creates a new Time Track, which is used to vary the speed of playback over time.

Stereo to Mono  — This command mixes current stereo track into a mono track.

Mix and Render — This command mixes all of the selected tracks together. If you are mixing stereo tracks, or mixing tracks that are marked as Left or Right channel, the result will be a stereo track (two channels), otherwise the result will be mono.

Your tracks are implicitly mixed whenever you hit the Play button and whenever you export. This command offers a way to do it permanently and save the results to disk, saving on playback resources.

Note that if you try to mix two very loud tracks together, you may get clipping (it will sound like pops, clicks, and noise). To avoid this, drag the gain slider on the tracks down to reduce their volume before mixing.

Remove Tracks — This command removes the selected track or tracks from the project. Even if only part of a track is selected, the entire track is removed. You can also delete a track by clicking the X in its upper-left corner. To cut out only part of the audio in a track, use Delete or Silence.

Align Tracks... — All the Align functions work on whole tracks or groups of tracks, not on selections, even if they span across multiple tracks. They all operate by time-shifting tracks (moving them left or right), making it easier to synchronize tracks or get rid of silence at the beginning. The cursor or selection stays in the same place unless you use "Align and move cursor...", below:

Align And Move Cursor... — same as the functions above, except that the cursor or selection is moved along with the tracks. That allows you to shift the tracks without losing your relative place.

Add Label At Selection — This menu item lets you create a new label at the current selection. You can title the label by typing with the keyboard and then hitting "Enter" when you're done.

Add Label At Playback Position — This menu item lets you create a new label at the current location where you are playing or recording. Do this if you want to mark a certain passage while you're listening to it. You can title the label by typing with the keyboard and then hitting "Enter" or "Return" when you're done. Only available whilst Audacity is playing.