Hi, I read this wonderful theory in 1 of the tutorials by "Dennis"- The Bhangra King regarding intervals. Following is a part of that theory. -------- Perfect Intervals: Lets take a Cmajor scale= C(1)--D(2)--E(3)-F(4)--G(5)--A(6)--B(7)-C(8). (- indicates a half step,i.e a jump from say Cto C# or E to F) The 1st note C is the root. The 8th note which again is C is called the Octave. The Root,4th,5th and the Octave are our Perfect Intervals. The 4th note is called the Perfect Fourth and the 5th note is called the Perfect Fifth(ie. Perfect 4th w.r.t our root which is C in this case) ---------- I read another theory by "amit82cse" regarding missin fret technique to find out the scale for a particular song. it says first we must write the scale, so lets take an example of C scale, it goes, C D E F G A B. Now the next part is to convert this scale using Major minor minor Major Major minor Dimnished technique. So according to that the final C scale would be C Dm Em F G Am Bdimnished. Question: Why are the two scales different, or is it possible to have two diff scales for a same key? Some one please explain. Thanx to all those who built this wonderful site for guitarists Cheers to all.