The early Christian church developed a system of eight musical modes (the octoechos), which mediaeval music scholars related to the ancient Greek modes. Misinterpreting the Latin texts of Boethius, medieval modes were given the wrong Greek names. Thus, in medieval and modern music, the Dorian mode is a diatonic scale or musical mode which corresponds to the white keys of the piano from "D" to "D". It may be considered an "excerpt" of a major scale played from the pitch a whole tone above the major scale's tonic (in the key of C Major it would be D, E, F, G, A, B, C, D), i.e., a major scale played from its second scale degree up to its second degree again. The resulting scale is, however, minor (or has a minor "feel" or character) because as the "D" becomes the new tonal centre the minor third between the D and the F make us "hear minor". If we build a chord on the tonic, third and fifth, it is a minor chord.
The formula for this can be shown as:
Examples of the Dorian mode include:
The Dorian mode is symmetric, meaning that the pattern of tones and semitones (T-s-T-T-T-s-T) is the same ascending or descending. The difference between the Dorian mode and the modern natural minor scale is well exemplified in the relative "hardness" of the 6th note of the tune. In the modern minor scale, this note would be a semitone lower.
The Dorian mode is equivalent to the natural minor scale (or the Aeolian mode) but with the sixth degree raised a semi-tone. Confusingly, the medieval and modern Dorian mode is the same as the Greek Phrygian mode.