It doesn't have to be a mini game, just an animation. I could care less about playing the instrument as a mini game. And there's more than two songs in the game. Ragnar The Red, Age of Oppression, Age of Aggression, The Dragonborn Comes, and Tales of the Tongues. So there's 5. When they add this feature, they could also add another song.
Ha!...Yes, well...When I said two that was not to be meant as an exact figure. Besides...5 is not any better.
I would, however welcome a questline for the Bards. It seems that it was something that was either scrapped at the last min, or not finished. That would be fine, as long as I am not forced to tap combos along a bouncing ball. Then I really don't know what else you would do with that.
I guess one can always choose to not do it...right? I am all about player choice and options. As long as it remains so.