Start the application without loading anything. Now go to the top menu and click on ‘Project’, then in the drop-down menu click on ‘Import Audio’. Wait for the program to process the audio and import it into the project, as the progress bar fills up. Repeat this procedure until all the audio tracks which you want show up in the project.
Now you have different tracks in your project all ready to be processed as you wish. You can see your tracks in the main window, each one with a different name/number depending on the order you imported them. On the left-side you have information about the track’s bit-rate quality and others, and you also have Mute and Solo buttons.
Lastly, click on either Mute or Solo. In the case of the former it makes no difference if you only have two tracks in your project, since one track will be muted and the other will play. If you have multiple tracks it may be easier to just select one and click on Solo. You can also use the Mute button if you have five tracks, for example, and need to hear how only two of these sound in a mix.
Either way, it really is as easy as that, the two buttons have a similar function. Now you know how to play a single track in Audacity.