Leadership by a group: In contrast to tolerating leadership as a position of authority, some highly successful organizations have adopted a pragmatic approach when they found that the role of boss costs too much in team performance. That is, in some situations, the maintenance of the boss is too expensive by either draining the resources of the group as a whole or impeding the creativity within the team, even unintentionally.

For example, the Orpheus orchestra, which has performed for over thirty years without a conductor--that is, without a boss--for a team of over 25 members, has drawn discriminating audiences, and has produced over 60 recordings for Deutsche Grammophon in successful competition with the other world-class orchestras with the autocratic or charismatic conductors

Referential papers: The Conductor-less Orchestra by Harvey Seifter.
Seifter's interview