Should power chord be play on the down beat?
# 1
What do you mean? You can play them whenever you want. Just as long as it's within the rthym of the song.
# 2
In my oppinion, power chords can be played on both or either beat. This also depends on songs you are playing. You can see differences especially in Reggae, Funky Rock which also uses both up-down beat.
*Aliens Understand Music*
# 3