Here you can link to your beepbox songs you made by inserting a button, then copying the unique super long web address on beepbox with your song open, then pasting it to the button link.
You can also try inserting your song as a .mp3
First add your audio file to your Google Drive in mp3 format.
Open the file in your Drive. Go to More Actions (Three vertical dots on the top right corner) Share. Copy Link.
In Google Sites, open the page your want to add the audio to. Click on Insert. Embed. URL. Paste the link to your audio file and click insert.
Done!