"Chelsea (Hold Tight)"

From TheChels.info - The Chelsea Football Club Wiki

This was a commonly heard chant at Chelsea games for decades; a simple repetitive clapping tune to the tempo of "Hold Tight" the 1966 hit record by Dave Dee, Dozey, Beaky, Mick & Titch (YouTube link). Previously used by the supporters of most clubs, but infrequently these days.

Clap, clap, 
Clap-clap-clap, 
Clap-clap-clap-clap,
Clap, clap, 
(shout) Chelsea!

(repeat)