Gb maj9/Db
The Gb maj9 chord consists of the Gb (Perfect unison), Bb (Major third), Db (Perfect fifth), F (Major seventh) and Ab (Major ninth) notes, with Db as the bass note.

How to play the Gb maj9/Db chord
- Play Db as the lowest bass note in the left hand
- Find Gb (Root) on the piano keyboard
- Add Bb (Major third) — 4 semitones above Gb
- Add Db (Perfect fifth) — 7 semitones above Gb
- Add F (Major seventh) — 11 semitones above Gb
- Add Ab (Major ninth) — 14 semitones above Gb
- Press all 6 notes simultaneously to sound the Gb maj9/Db chord