I Know Why (And So Do You) in B

Glenn Miller(1941)swing
Do Re MiC D E
A
B

Chord Diagrams — I Know Why (And So Do You) in B (Guitar)

Display
FingerNoteDegree

I Know Why (And So Do You) in B

Key of B

B major mixes barre and open elements. The B chord itself is a barre at fret 2, but E and A are comfortable open chords forming the IV and V. The open B string rings as the root, allowing creative drone-based arrangements. B is a intermediate-level key on guitar because the open B string rings as the root and the open E strings provide the 4th — useful for sus4 voicings and drone effects. This key mixes open and barre shapes, making it a good intermediate challenge that builds fretboard fluency.

Voice Leading

The bass line moves through B to G# (descending minor third), G# to C# (ascending perfect fourth), C# to F# (ascending perfect fourth), F# to B (ascending perfect fourth), B to E (ascending perfect fourth), E to D# (descending half step), D# to D# (ascending unison), D# to G# (ascending perfect fourth), G# to F# (descending whole step), F# to C# (descending perfect fourth), C# to C# (ascending unison), C# to F# (ascending perfect fourth), F# to G# (ascending whole step), G# to C# (ascending perfect fourth), C# to B (descending whole step), B to A# (descending half step), A# to D# (ascending perfect fourth), D# to C (descending minor third), C to A# (descending whole step), A# to D# (ascending perfect fourth). A half-step bass movement creates a strong leading-tone pull that demands resolution. The root motion by larger intervals (fourths and fifths) gives each chord change a strong, decisive character. When the progression loops, the bass returns from D# to B by major third.

Scales for Improvisation

B major pentatonic works because every note is either a chord tone or a safe passing tone — there are no avoid notes. For soloing, this means you can play freely without clashing. Over dominant seventh chords, B Mixolydian adds the flat seventh for an authentic blues-rock edge.

swing4/4 · 29 bars · Form: AB

Chords: B, G♯m, C♯m7, F♯7, B7, E, D♯7, D♯m7, G♯7, F♯7♯5, C♯9, C♯m7♭5, F♯7♭9, G♯m7, C♯dim, Bm, A♯7♭9, D♯m, Cdim7, A♯7, D♯7♭5.

Scales for Improvisation B bebop, B bebop major.

Diatonic chords: See all chords in the key of B