I remember the Major pentatonic as the Major scale less the 4th and 7th notes; these are the two that will get you into trouble in the wrong places.

If we look at the notes of the pentatonic scale, it is obvious why they work so well.

In the key of C Major our pentatonic is C D E G A.

Against our C Major triad (CEG), this gives us the D for the 9th and the A for the 6th plus our chord notes, so no problems for dissonance (notes that bite).

Against our F Major triad (FAC), we have the G for the 9th, the E for the 7th, the D for the 6th, and the A and C are the other chord notes; again, no problems with chord tone clashes.

Against our G Major triad (GBD), we have the A for the 9th and the E for the 6th plus the chord notes.

So blaze away with your pentatonics with the knowledge that those notes will work and that they are everywhere!

Pentatonic Video - G Major

Cheers,
SarinaJ :)