To learn Christina Aguilera - Aint No Other Man chords, anchor your practice on these foundational sequence of chords - B, G#, B, F#m and B. I suggest starting at a calm pace of 64 BPM, and as you gain confidence, approach the song's BPM of 128. With F# Minor as the song's key, tweak the capo to cater to your vocal pitch and chord likes.