Notting Hill Carnival, Europe's biggest street festival, gets underway earlier than usual this year, starting at 9am. Hundreds of thousands of revellers are descending on west London to watch costumed masquerade artists, steelpan bands and international DJs perform along the three and a half mile route. Historically steel bands, Soca & Calypso Music have been at the heart of the Carnival but in recent years these have been overtaken by the static sound systems playing anything from Reggae to R&B, Funk, House and Dub. Live stages also feature local bands, top international artists and sounds from around the world. Organisers have been advising people to turn up early to avoid missing any of the show. Police have already said there will be a major security operation around the event. Officers will man a series of security rings to target known troublemakers and flush out anyone carrying guns or knives. Over 150 people have been sent letters telling them to stay away and 16 suspects have been arrested in the run-up to the event. Chris Boothman, the event's lead director, said: "Carnival gives revellers of all ages and backgrounds the chance to come together and celebrate three days of unique, free, and fun-filled entertainment and this year promises to be a spectacular event that is unrivalled anywhere in Europe." London mayor Boris Johnson said: "This year I encourage you all to arrive early to enjoy the colourful floats and the sounds of the massed bands and steelpans.There really is no better place to sample delicious Caribbean food and enjoy the dazzling colours of the costume parade. I hope everyone has a truly wonderful time at the carnival this year."