Knock On Wood by Eddie Floyd is in A at 120 beats per minute and runs 1:51 across 20 bars. It uses 9 chords — E, G, A, B, D, E7, F#, G#, 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.