B♭ – C – D – E♭ – F – G – A♭ – A – B♭
Where you are with it
Bb7 · Bb13 · bebop lines
Mixolydian plus a passing natural 7, so eighth notes land chord tones on the beat.
Band calls concert B♭? On B♭ trumpet play C.
● valve down · ○ valve up