Sound is an important tool in your robotic toolkit, but you will want to do more than just play music. Let's allow your robot to speak.
Now that you can both get sound in and out of your BeagleBone Black, let's do something useful with this capability. You're going to start by enabling eSpeak, an open source application that provides you with a computer voice.
eSpeak is an open source voice generation application. To get this free functionality, you'll need to do the following.
Download the eSpeak library by typing
sudo apt-get install espeak. You'll probably have to accept the additional size space that the application requires, but this is fine ...