Where to capo for Bb Lydian
Put the capo at fret 5 and play Bb Lydian using F Lydian shapes. That is the easiest of the eight positions ranked below, and it is what most players reach for. Against playing Bb Lydian open, it drops the mean difficulty of the key's seven chords from 4.7 to 3.4 and gains 4 ringing open strings.
You want Bb Lydian. Capo 5 and play in F Lydian.
All eight positions, ranked
Each row transposes Bb Lydian down by that many frets to find the shapes your hand would actually make, then scores the best voicing of all seven chords — fewer fingers, less stretch, closer to the nut, fewer muted strings. Lower is easier. Standard tuning (E2 A2 D3 G3 B3 E4).
What you are playing
The seven seventh chords of Bb Lydian are BbMaj7, C7, Dm7, Em7b5, FMaj7, Gm7, Am7 — the ones the ranking above is scored against. Explore this key on the Bb Lydian key page.