@Rai:
That made me lol =P
Okay people, I keep seeing here posts indicating Brooke is a swordsman.
I call undefined fact!
I've said it so many times before, just look how Brooke cut Talaran. Look at it [DON'T DROOL! SNAP OUT OF IT!].
Brooke cut him with a fine line from the top. Zoro would never do that, and I doubt he'd even bother reaching there. I doubt Brooke bothered reaching there.
I say he used sounds. Why would I say so?
While we know Ryuuma used Brooke's fighting style, we also know Ryuuma used an attack that only happened after Team Useless stepped for ten feet [or something like that].
I think many people already thought of it but I'd say it anyways, since there's no other way for an attack happen in the future with no time indication, without someone performing it, he must have made the attack and put the condition on it only to come true after ten feet's worth of walking sound have been made.
So that means Brooke is USING SOUND AS HIS WEAPON AND SWORD AS MERELY A TOOL. =O
Arrghhh I suck at English so much, but please bear with it. ^^
This is far-fetched and unlikely. If Zoro's swords can unleash full whirlwinds, attack from a range with air slahes and create illusions, there's absolutely no reason why Brook can't do the same. Swords in One Piece are used to do epic things. Mihawk didn't have to jump when he cut Krieg's ships in half and yet his cuts still had to reach very high vertically.
Seriously, I find it lame that you're trying to defend sound-based moves using the direction of the cut as an argument. How is sound vertical? Sound waves spread in spheres and need some kind of vibration to actually be sound. Brook's cut was clean, there was no shaking of the floor or blurred vision or sfx to hint at sound. And we've seen it twice, Ryuuma used it first and still there were no hints that it was anything but a sword-move.
The delayed attack has been done dozens of times in shonen (I bet you can find an example in Rurouni Kenshin) and it's always been explained as just having a kickass technique with a sword, which is good enough for shonen logic. There's no need for a sonic explanation when a simple sword-cut could do just the same thing.
Sure, Brook doesn't use swords 100% the same way as Zoro, but that's a given, since Zoro uses three swords and Brook only one. Your theory has no ground.