Db maj7
The Db maj7 chord consists of the Db (Perfect unison), F (Major third), Ab (Perfect fifth) and C (Major seventh) notes.

How to play the Db maj7 chord
- Find Db (Root) on the piano keyboard
- Add F (Major third) — 4 semitones above Db
- Add Ab (Perfect fifth) — 7 semitones above Db
- Add C (Major seventh) — 11 semitones above Db
- Press all 4 notes simultaneously to sound the Db maj7 chord