Knock On Wood by Otis Redding is in A at 128 beats per minute and runs 2:15 across 38 bars. It uses 12 chords — E5, G5, A5, B5, D5, A, E, C#m, and a few more. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? Knock On Wood guitar melody tab.