If you are selling your original music, CDs, or audio tracks on Teachers Pay Teachers, you will want to provide a sound preview for your product listing.
You can protect your work from infringement by adding a simple digital watermark, which I have created and you are free to use without restriction.
The download includes both an 8 second clip and a 60 second sound clip (both in mp3 format). Use a Digital Audio Editor such as the free Audacity (http://audacity.sourceforge.net) to easily add the TpT watermark to a preview version of your product. Export your preview music with the watermark to mp3 format to include in your product preview.
I have included a sample of my music with the watermark applied so you can get an idea how to use this.
Let me know if you find this useful.