Originally Posted by: stevelaba[p]The Scale Finder is a reference tool. It shows you all of the notes of any given scale in one fretboard position. It's possible to play the C major scale using all the strings on frets 5 through 8. And it just happens that if you play it in that position there are 2 lower notes available on the low string.
I see that a Major scale start and ends on the root note.[/quote][p]Yes. As a conceptual unit you learn what notes and intervals a scale consists of. And then you start to play it from one root note up to the next root, or starting at the higher root note, then down through the scale notes to the lower root note. That helps you understand the essence of a scale. What it is and how it sounds.
However, any scale can be continued beyond either root note as high or as low as the musical instrument allows.
[quote=stevelaba]
But when looking at the patterns on the strings and frets for the C Major scale I see the A and B on the low E string just before the C note on the 8th fret.
Why are those 2 notes there?
The Scale Finder is not a teaching or pedagogical tool. It's simply a reference tool that you can use to find all the notes available.
In real music you will find that you don't always play an entire scale from root to root and then stop. Usually melodies start and, or stop in the middle of a scale. So it can be handy to know that any given scale extends above and below its root notes.
Hope that helps!