To learn Ella Mai - One Day chords, your first step should be understanding these chords - Bb, Ebm, B, Ebm, B, Bbm, Eb, Bbm and Ebm in sequence. Kick off your practice at a gentle 94 BPM, then escalate to the song's tempo of 188 BPM. With the song's key of Eb Major, set your capo to fit your vocal range and chord choice.