I call them "Trigger's broom" bands: pop groups that have changed line-ups so many times that there are no original members left.
The name is a reference to this scene from Only Fools and Horses:
We can now welcome Sugababes into the ranks of Trigger's broom groups. On his Telegraph blog, my colleague Neil McCormick points out that the club already includes The Drifters, Yes and The Blind Boys of Alabama.
As Trigger says: "This old broom has had 17 new heads and 14 new handles in its time."
I wonder how long the Sugababes' new head will last?