Cluster One" is the opener.

That’s the name of the ambient soundscape piece that opens Pink Floyd’s The Division Bell. It’s a mostly instrumental track—no vocals, just Gilmour’s slow, atmospheric guitar and Wright’s keyboard textures setting the mood for the whole album.

It came from a jam session, and the band liked it enough to lead with it. Fits the album’s theme of communication and silence—or lack thereof. If you’ve heard it, you know it’s the one with the wind and the distant electric piano.

Not their most famous opener, but a good one.