Originally Posted by: Philip CharlesActually, why I switched to minor & major is, I thought when changing from B to key F Major chords are the i iv v F B C respectively[/quote]

2 things here.

1. Major chords are labeled with upper case Roman Numerals: I - IV - V. Minor chords are lower case: ii - iii - vi. Diminished is also lower case: vii dim.

2. The 4th scale degree in F major is B-flat (Bb). So the IV chord in F major is B-flat major.

[quote=Philip Charles]Minor chords are the ii iii vi G A D respectively, so I thought when transposing B all minor and major should accompany with the key of F.

The order of chord qualities does not change when you change key.

This tutorial covers harmonizing the major scale, chord quality & chord progressions within a key.

https://www.guitartricks.com/tutorial.php?input=2387

In all 12 possible major keys this is always true:

I - "1 chord" is Tonic (or Root)[br]ii -"2 chord" is Sub-Dominant[br]iii - "3 chord" is Mediant (or Intermediant)[br]IV - "4 chord" is Sub-Dominant[br]V - "5 chord" is Dominant[br]vi - "6 chord" is Intermediate (or Sub-Mediant)[br]vii dim - "7 chord" is Dominant

So, in the key of B major these are the chords:

B major chord (I)

C# minor chord (ii)

D# minor (iii)

E major (IV)

F# major (V)

G# minor (vi)

A# diminished (vii dim)

And in the key of F major these are the chords:

F major chord (I)

G minor chord (ii)

A minor (iii)

B-flat major (IV)

C major (V)

D minor (vi)

E diminished (vii dim)

Always the same order of major & minor chord qualities. Only the letters change. Make sense?