Blathers works too.
Interestingly, the two versions of R.O.B. allow for two different color schemes but only one Yarn Yoshi design shows up at a time. The color scheme displayed depends on the last R.O.B. to be scanned.
@Xdqwerty, Osu! Tatakae! Ouendan! is the Japanese version of the game, different settings/characters/songs but otherwise identical mechanics. I played that before I knew about Elite Beat Agents lol. Both fantastic games https://en.wikipedia.org/wiki/Osu!_Tatakae!_Ouendan