So what is "stock"? To borrow an explanation from stockphotosecrets.com.... "Stock [images are] existing [images] –already created– made available for license by paying a fee to both the artists that produced them and the stock agencies managing them, acquiring the right to use them legally in different ways, while the author retains the copyright of their work.". Source: about 3 years ago

Somehow had a client post a non-final version of a video that still had the "premiumbeat.com" watermark on the music.... Source: about 1 year ago

Most likely a royalty free backing track from premiumbeat.com. Check out this post for more music. Source: about 1 year ago

If you just want to find tracks to add to your "show library", check out PremiumBeat. I got a few tracks there to use as interludes for a voiceover project I did for my last corporate job (invoiced them for it too!). Source: over 1 year ago

He uses premiumbeat.com a lot. I was able to find some of his used tracks over there. I'm sure this one is there as well. Source: about 2 years ago

It's a stock track. Places like premiumbeat.com are popular for searching for ad tracks. You might be able to email them and inquire. Source: over 2 years ago