Originally Posted by: lifeis@songis the major pentatonic and the minor pentatonic scales the same thing except in different positions? and if so then arent all modes that are based upon major scales, just more complicated, and built upon versions of the petatonic scales? im just a little confused on this whole mode business.

I am going to try to answer your questions:

a) The Major Pentatonic Scale and the Minor Pentatonic Scale are not the same.
Let's take a look at the C major scale first.
C-D-E-F-G-A-B
1-2-3-4-5 -6-7

Now, the Major Pentatonic Scale includes the same notes as the major scale, but leaves out the 4th and 7th degrees.
C-D-E-G-A
1-2-3-5-6.

The Minor Pentatonic Scale leaves out the 2nd and 6th degrees; and, the 3rd and 7th degrees are each flat(a half step lower).
C-Eb-F-G-Bb
1-b3-4-5-b7

b) The ancient Modes are not built upon versions of the petatonic scales. They are seven note scales.
For example the Dorian Mode, is a minor mode which has the 3rd and 7th degrees flatted.
C-D-Eb-F-G-A-Bb
1-2-b3-4-5-6-b7