F m11/Bb
The F m11 chord consists of the F (Perfect unison), Ab (Minor third), C (Perfect fifth), Eb (Minor seventh), G (Major ninth) and Bb (Perfect eleventh) notes, with Bb as the bass note.

How to play the F m11/Bb chord
- Play Bb as the lowest bass note in the left hand
- Find F (Root) on the piano keyboard
- Add Ab (Minor third) — 3 semitones above F
- Add C (Perfect fifth) — 7 semitones above F
- Add Eb (Minor seventh) — 10 semitones above F
- Add G (Major ninth) — 14 semitones above F
- Add Bb (Perfect eleventh) — 17 semitones above F
- Press all 7 notes simultaneously to sound the F m11/Bb chord