data accessed by youtube

Using my iPad mini with the latest iOS release, I noticed that by accessing youtube with, the youtube page shows me a choice of clips which match exactly the music I have stored on the said device, artists and/or titles.

I do not have any history of looking for these pieces of music either with a browser or though youtube. I suspect that youtube is reading my private data on the device in some way.

Can somebody enlighten me on this?

Thank you

JPB