Rhythm Blade [ddi] bonus to AC and Reflex work when you've not got an existing shield?
Property: While you wield this weapon in your off hand, your shield bonus to AC and Reflex increases by 1.
I've seen it argued both ways, but if it works without an existing shield, why would you ever go for the
Shielding Blade [ddi]
Property: You gain a +1 shield bonus to AC.
which is a Level 4 magic item, as opposed to the
Rhythm Blade Level 3