There's no need to flail wildly on the drums during a BRE unless you feel like it. You will end up with pretty much the same score whether you hit 40 notes a second or 5 notes a second.
So just try and jam out with the song, make up some cool fills, and have fun.
They designed it like this so that the drummers could be creative and not have to just spam the drums.
_________________
My XBL Gamertag - m4tth4x
Drum Goals-
Get 1st place on a song [X] (Even the Losers and Here Comes My Girl (Live))
Guitar Goals -
FC Chinease Democracy [ ]
FC Godzilla [X]
FC Chrion [-1]
FC Mud On The Tires [X]
FC Tripolette [-2]
Add me on XBL if you wanna play RB/GH