Breakin' Convention 06, Sadler's Wells, London

Breakin' Convention, the hip-hop dance festival held at Sadler's Wells, has been a runaway success for the theatre. Besides the sell-out festival weekends, a busy programme of performances, workshops and classes, Breakin' Convention is expanding. Its associate companies are giving increasingly high-profile performances in the rest of the year. Jonzi D, the festival curator, recently toured his own production, TAG.

Jonzi D and his colleagues are tapping into a large existing audience for this music and dance styles, but they also insist on hip-hop's theatrical side. Breakdancing emerged in the 1970s, but is still having teething problems as a theatre form. The different dance styles are full of spectacular moves, and there are plenty of fine dancers. The difficulty is in building longer theatrical sequences.

Sometimes this doesn't matter. Last Saturday, the Swiss group Deep Trip made their British debut with Les Clochards (The Tramps). The show's attempt to suggest street life is perfunctory, limited to some cardboard boxes and a few rips in the dancers' clothes. The promised messages, about working together and strength in adversity, are woolly at best.

Yet Deep Trip fit in some dancing that makes Les Clochards one of the best shows. A core group of dancers stalk and strut, with soloists bursting into the spotlight. When a conventionally dressed man is turned into another hip-hop dancer, he starts with shifting robotic moves, his body changing as we watch.

Solos had more impact than group dances. The British group Flawless, winners of UK and international championships, look like the background of any hip-hop video. Their unison dances are weightlessly slick but lack bite.

Jonzi D aims to show the range and variety of hip-hop dance. There are successful appearances by youth groups, national and international companies, plus a sense of hip-hop's past. This year's veterans were Medea Sirkas, led by Boogaloo Dana, who pioneered several styles in the 1970s. The Medea Sirkas dancers, dressed as sci-fi creatures, bounce on the spot or move in robotic unison. The steps are surprisingly simple: it's like hearing early Eighties drum machines.

Solo for Two, by the German dancer Storm, is livelier. Using a video screen, he dances with a film of himself, and with film of Berlin.

The French group Wanted Posse had a harder time with Transe. The audience was ready to applaud the handstands, but very restive during the slow build-ups.