On the Stradella bass system, diminished 7th chords are also minor 6th chords
AKA: B diminished seventh, B°, Bdim, Bdim7, Bdim7th, Bdim/6, Bdim(add6)
Green bass pattern: Bdim7(omit5) = Bm6(omit5)
Blue counter bass pattern: Bdim7
Notes:
B, D, F, A♭
Bdim button plays:
B, D, A♭ (no F)
Intervals:
R, m3°, m5°, dim7°
Dim buttons play:
R, m3°, dim7° (no 5°)
Left hand:
Green bass pattern:
Bdim7(omit5), same as Bm6(omit5)
B + Bdim
(C♭ + C♭dim)
Blue counter bass pattern: Bdim7
B + Fdim
Fingering:
4 + 2