Sampled from youtubes royalty free collection.. these are the terms of service here:

Additional terms and conditions
Your use of this music library (including the music files in this library) is subject to the YouTube Terms of Service. Music from this library is intended solely for use by you in videos and other content that you create. You may use music files from this library in videos that you monetize on YouTube.

By downloading music from this library, you agree that you will not:

Make available, distribute or perform the music files from this library separately from videos and other content into which you have incorporated these music files (e.g., standalone distribution of these files is not permitted).
Use music files from this library in an illegal manner or in connection with any illegal content.
Additionally, some music files from this library may be subject to additional requirements as set forth in the library (e.g., attribution requirements). You agree to comply with such requirements when you use music from this library.

I am imagining that a "remix" constitutes "content" and is not standalone distribution in any way.. If it doesn't work like that I'll gladly take this down.