There are two tetrachords in a diatonic scale. The second tetrachord has the higher four notes. In D major, they are A B C# and D.
The supertonic of any scale is the second degree of the scale. Therefore, the supertonic of C major is D.
The leading tone is the seventh note in the scale. For D-flat major, this would be C.
In a major key, the triad built on the 7th scale degree is diminished. Using C major as an example, the triad on the 7th is B D F. B to D is a minor 3rd, as is D to F, so B to F is a diminished 5th.
Generally, the leading note is the seventh tonal degree of the diatonic scale leading up to the tonic. For example, in the C major scale (white keys on a piano, starting on C), the leading note is the note B; and the leading note chord uses the notes B, D, and F: a diminished triad. In Music Theory, the leading note triad is symbolized by the Roman numeral vii°.
The note "A"
There are two tetrachords in F Major F, G, A, Bb then C, D, E, F
The 2nd in C major is D.
D natural
The supertonic of any scale is the second degree of the scale. Therefore, the supertonic of C major is D.
G major transposed down a major second becomes F major. In the G major scale, the notes are G, A, B, C, D, E, and F#. When you lower each note by a whole step (major second), the resulting scale is F, G, A, Bb, C, D, and E.
You can have a musical scale starting anywhere you like. On the piano, the simplest scale is C major, in which the second note is D. In all major and minor scales, you can find the second note by moving up two semitones from the first note (C-C#-D or G-G#-A)
The D major scale has F# and C#.
Common chord shapes in D major tuning on the guitar include D major, G major, A major, B minor, and E minor. Common scales used in D major tuning include the D major scale, G major scale, A major scale, B minor scale, and E minor scale.
Common chord shapes in D major guitar tuning include D major, G major, A major, B minor, and E minor. Common scales used in this tuning include the D major scale, G major scale, A major scale, B minor scale, and E minor scale.
The D Major scale has two sharps, F and C. The notes in this scale are D, E F sharp, G, A, B, C sharp, D.
The subdominant note is D in an A major scale
The pentatonic scale has 5 notes. It is similar to the omission of subdominant and leading note of major scale. Starting from D, the scale is D E F# A B.