Google currently doesn't have an "Add Audio" feature for Google Slides. What it does have, though, is an "Add Video" feature. So I pull up a song I want for background music off of YouTube. You probably are aware already, but if not, you can find all sorts of background music to match whatever mood you wish to establish.
OK, so when I made a Slides presentation on Norse Ragnarok for my mythology class, I wanted to tell the story of Odin's fight with Fenrir. So I found a great image to post on the screen and I wanted some cool music in the background while I'm in story-telling mode. After a search on YouTube (and getting way too sidetracked on listening to several different awesome background songs), I found one and copied the URL. Then I hit the INSERT option at the top of my Google Slides and chose VIDEO. You can search YouTube right there on Google Slides, but I prefer to find it on YouTube, catch the URL and then stick that into the URL search.
However, when I place it in the slide, it is way too big. That's OK. We will take care of it in a minute.
Now, we want the music to start automatically, so we need to click on the video, select FORMAT, and then FORMAT OPTIONS.
Under the FORMAT OPTIONS tab, click VIDEO PLAYBACK. Notice that here you can choose a time in the video for your song to start or you can just start it from the beginning.
Now you need to click the AUTOPLAY WHEN PRESENTING box and it will start immediately.
Extreme Pro Tip - It is a good idea to select the AUTOPLAY option when presenting and slide that has a video. It makes for a smoother presentation.
Now we need to get the video out of sight. So we will now shrink the box down and move it to a corner.
It will not be completely out of sight, but when the slide presents, it will be virtually unnoticeable and, at the very least, unobtrusive to those that do notice it.
This is what your audience sees.
Now all that is left is for you to drop a link for the music in the notes section of your slides right under your image attribution.
Extreme Pro Tip - Each semester, before presenting the slide, do a quick run through to make sure your songs are still active on YouTube. Sometimes people's accounts go down or they didn't have permission to host that song and the link is now dead. Of course, it is a good idea to do this anytime you have a video, for viewing or for listening, in your presentation.
Have a cool tip? Share it! Have a different way of putting music on the slides? Share it! Found it useful? Let me know!