The idea is to (randomly) start each audio clip via a trigger and be able to click on another trigger to stop the previous audio from running.
Insert all the necessary audio using Insert - Audio - Audio on my PC. Replace the loudspeaker icon (if you want to) by right clicking the loudspeaker icon and choosing Change picture or click the Format tab under Audio tools and click Change picture icon. Browse using Bing to insert the picture.
Add the textboxes that will act as trigger to play the audio. You can give them an appropriate name by pressing Alt+F10 to activate the Selection task pane. Here I just choose the name of the song.
After inserting the audio clips the animation pane looks like this:
You can click the sound clip to play it. Clicking another will not stop the previous one. To change this we will add a trigger to each text box. Select the audio clip, Animation tab, Trigger button, next to On click of choose the name of the trigger (=name of the text box).
Repeat the process for the other audio clips.
In the animation pane the name of the trigger appears next to the title of the audio clip.
To stop each audio clip and start another we will have to add a stop animation to all the other audio clips.
Select the audio clip and click the Add animation button on the Animation tab. Select the Stop icon and drag the animation below the desired audio clip.
Next to the item Start in the Timings group choose with previous.
Start your presentation and click a random trigger (text box), wait a few seconds then click another trigger (text box), the previous audio clip will stop. You can repeat the same operation several times on the same slide.