Really? I thought it was about building skills by just applying yourself. You don't learn guitar or Ruby in a night. You practice and play with them for years and integrate them into your projects.
However, if the robot could create new algorithms on the fly and could use them to tweak the way it played the guitar for the better, then we could say it is a creative robot.
Creative guitar players, like the second robot, invent new ways of playing a particular piece of music, or just a few seconds of it, to induce specific reactions in the listeners. This is creativity, and it seems to be rare not common, possibly because of how difficult it is to master the notes, and then to build rapport with the audience and manipulate their emotions.