Is interval always related to a scale?

Question

Is music interval always a concept in terms of scales and do we always have to take the first note as tonic? What would be the interval between D note and E note in C major scale?

Answer 1

Hi! Not really, it is based on diatonic fundamentals. We can take C as the root note and D would be a major 2nd and E would be a Major 3rd (up). However Db would be minor 2nd and Eb would be minor 3rd, these are not in C Major scales. Intervals measured by distance in between them regardless of the scales. Also you find different intervals when you reversed them. G above middle C is up a 5th but an octave lower G to the middle C is down a 4th. Does it make sense?