The Web 2.0 philosophy has brought new ways of using the web as a content repository and a sharing platform. Non-computer skilled people can now publish their own text, images, videos and/or sounds and take part in communities created around topics they like. Our idea is thus to use this new communication mechanism to assist skill learning. Skill is indeed a difficult knowledge to learn on a text form as it is hard to describe movements, gestures or procedures in this way: sometime, a picture or a video is better than a  thousand of words.
As a popular field of experience, we have focused our attention on music learning, and more particularly on guitar pieces learning. Music is very representative of skill learning, it is both a physical and an intellectual activity. The “Gloss2U” service we describe in this article takes into account the specificities of this learning process, especially as events are time-related.

To achieve this, we rely on new equipment conditions that are nowadays gathered. Userfriendly multimedia tools opened new horizons and broadband networks (ADSL, cable, …) are becoming more and more common. Almost everybody is a potential content producer with just a webcam or a cell phone. Our system is therefore audio and video based and users interact with each others by submitting contributions, called glosses, in the context of the piece they are learning. A dialogue starts between student users (learners) and experimented ones (professors), to discuss encountered problems and the way to solve them. The other strength of this system is that it can act as a knowledge repository for forthcoming practitioners.