To the list of things Irish — soda bread, whiskey, corned beef and cabbage, U2 and Daniel Day-Lewis — add "Riverdance."

The Irish cultural sensation is all about the ecstasy of the feet — step dancing with unified cadence, creating a tapestry much like a "42nd Street" musical lineup of dancers on steroids. With "Riverdance" the flow mostly is swift, frenzied and constant, like a gushing river to which the show owes its name.

There’s a collision of sound and movement, but a happy one; the music is richly Celtic but with occasional soft-as-silk vocal variations and periodic departures into the realm of flamenco dance. Even bluesy tap executions reminiscent of Greg­ory Hines or Savion Glover are splendidly staged as a Celtic street-dance competition among five male dancers.

The production, which opened Wednesday night and runs through Sunday at the Blaisdell Concert Hall, features two dozen dancers who frequently move as one synchronized unit, engaging in stunning precision and galvanized by tradition.

It is high-energy, high-octane, high-voltage stuff. The amplified footwork sound heightens the excitement and the adrenalin.

"Riverdance" is rooted in Irish history. The name is derivative of a flowing river, with tributaries coming together the way cultures meld. The tradition taps Celtic tales, some with mythological influences.

The title song, which closes Act 1, is an evolutionary tale with historical relevance, as the full cast of dancers projects the power of flowing waters fertilizing, then flooding, barren land but prompting a burst of celebratory joy.

Lead dancers Craig Ashurst and Alana Mallon bring glamour and style in several numbers, showing workout agility in one instance, feeling the love in another.

Ashurst also is buoyant, at times springing into high leaps and twirling like a top. Mallon switches from balletic beauty to step-dancing sizzler in her solo turns.

Marita Martinez-Rey specializes in the rich tradition of flamenco, providing fiery and seductive twists with arms and hands help telling her stories.

Not surprisingly, the audience favorite is the aforementioned tap-challenge routine, dubbed "Trading Taps," where rigorous step-and-tap exchanges pit Michael E. Wood and Benjamin Mapp as soulful street dancers versus Ashurst, Padraic Moyles and Jason O’Neill as traditional step dancers.

The atmospheric musical score by Bill Whelan provides the colorful sound pallet thatblankets the production.

Happily, there are charming and revealing instrumental interludes by soloists in the five-piece onstage Riverdance Band, notably Patrick Manan on fiddle and Matt Bashford on the bagpipe-sounding Uilleann pipes.