I generally do not worry too much about the theory when I play but have started to take a bit more of an interest by startign to deconstruct some of the songs play.

I have been playing Tequila by the champs for a while now and when I played the notes for the main section, they roughly followed the Cm pentatonic. So I play an improvised solo over this section based pretty much on the Cm pentatonic and it all sounds good to me. However the chords are F and Eb. Therefore, I thought I was really playing the Eb pentatonic. But that didn't make sense to me. I assumed the key was F.

Then I read that the key actually is F Mixolydian as it is saxaphone friendly. I went to the scale tool to find that the notes I played were part of this scale.

Can anyone give me an explanation of the mixolydian scale/key.