"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!