Distributed music collaboration

An apparatus comprising a collaboration system that comprises a session hub and a server that is in data communication with said session hub and that is also in data communication, via a wide-area network, with a plurality of clients, among which are first and second clients that are used by corresponding first and second users, wherein said server comprises a filtering streamer, a first session transform, a second session transform, and a session vector that comprises session tracks that were provided to said server by said session hub, wherein each of said session tracks represents music that was played by a corresponding one of a plurality of musicians during a session, wherein said session vector has at least as many elements as musicians in said plurality of musicians, wherein said first and second session transforms comprise user-defined editing and mixing commands that were received from said first and second clients, respectively, wherein said filtering streamer is configured to receive said session vector as a first input thereof and to use said session vector as a common foundation for plural mixes by accepting said first session transform as a second input, streaming a first mix to said second client, whereby said filtering streamer accepts said first session transform and said session vector as inputs and outputs audio that can be listened to at said first client, thereby causing said filtering streamer to stream said first mix to said first client, said first mix comprising music from said session as modified by said first session transform, accepting said second session transform as a second input, and streaming a second mix to said first client, whereby said filtering streamer accepts said second session transform and said session vector as inputs and outputs audio that can be listened to at said second client, thereby causing said filtering streamer to stream said second mix to said second client, said second mix comprising music from said session as modified by said second session transform, wherein said first mix comprises said session vector as modified by said first session transform and wherein said second mix comprises said session vector as modified by said second session transform, wherein said server is configured to provide said first user with a user interface having a plurality of views and an interface element that permits switching between views in said plurality of views, wherein said views in said plurality of views comprise a time-line view, an annotation view, a mixing view, an editing view, and a human-readable music view, wherein said time-line view comprises a scrollable time-line having nodes corresponding to each session that said first user is authorized to access, wherein said nodes are ordered by times within said session, wherein each node is associated with a metadata field that shows said metadata associated with said session, wherein said annotation view displays session tracks in graphical form and marker points to mark selected points in each of said session tracks, wherein each marker point has an associated annotation window in which said first user enters information to be shared with other users, wherein, opening said annotation window reveals comments entered by said first user and comments entered by other users, wherein said mixing view displays, for each of several sessions, session transforms that have been saved by said first user and session transforms that have been saved by other users, wherein said editing view provides an interface to enable users to cut, copy, and paste selections within and between session tracks, to play, pause, fast-forward, rewind, and to position a play head, and to change levels within a specified interval for selected frequencies, and wherein said music view includes a scrollable time-line that has nodes, wherein clicking on a node causes display of a window showing a title, lyrics, notes, and chords associated with said session track.