TORONTO — Attracting younger audiences has become the Holy Grail for arts organizations around the world, but the National Ballet of Canada seems to be achieving that goal via a multipronged strategy involving everything from the Internet to Mick Jagger.For the second time this season, a mixed bill of three short works — normally the hardest sell in ballet — is playing to packed houses thanks to a populist jump-start provided by the signature piece. In November, “West Side Story Suite” drew capacity crowds to an all-Jerome Robbins program. Now, “Rooster,” Christopher Bruce’s saucy 1991 dance pieces set to eight songs by the Rolling Stones, is selling out as well. What’s fascinating is how the bait-and-switch approach is working here in a positive way. People who came to hear “Tonight,” stayed to cheer Robbins’ collaboration with Phillip Glass on “Glass Pieces.” And the Jagger fans who showed up for “Ruby Tuesday” are saving their loudest cheers for avant-garde Quebecois choreographer Marie Chouinard’s techno-robotic exploration of “24 Preludes by Chopin.” It’s the kind of eclecticism artistic director Karen Kain has been working toward since she took over the company from James Kudelka in 2005. During the Kudelka years, the programming was dominated largely by full-length pieces he choreographed himself. Although many of them were well received, they brought a certain monotony to the company’s style that resulted in declining auds. Arguably the country’s most revered figure in dance for her decades of stellar performances as a ballerina, Kain revamped the repertoire with a new breadth of taste and sensibility. She kept Kudelka’s snappier pieces in rotation, put the more turgid ones on the shelf and returned some other classic full-length ballets to the season. But Kain also felt the need to add edgier, more alternative colors to the mix. The upcoming year will showcase a visit from Alberta Ballet with its Joni Mitchell work, “The Fiddle and the Drum,” as well as a subscription season that combines John Cranko and Twyla Tharp with a trio of world premieres by Canadian choreographers. The ballet has also revamped its website (national.ballet.ca) to include generous videoclips from works past and present, allowing the casual Web surfer to see what the company is all about. And it’s also on the Internet that the popular DanceBreak program was launched (dancebreak.ca). Anyone between the ages of 16 and 29 can join for free; once they’re a member, they can purchase any unsold seat in the theater (excluding the Grand Ring) for C$20 ($20) on the day of the performance. It’s now a common sight in the orchestra of the sleek new Four Seasons for the denim-and-leather crowd to be seated alongside the wools and furs of traditional ballet subscribers. Witnessing the success of the National Ballet’s strategies, other Ontario arts groups have climbed aboard. The Stratford Festival now features live weekly webcasts on its upcoming season and has instituted the TiXX Program, under which 60 balcony seats for each performance in the Festival Theater are available online for $20. And Canadian Stage Company is offering a designated number of $20 seats for each performance, as well as a 50% off policy on unsold seats one hour before curtain time. “If you build it, they will come,” goes the mantra. But if you also make it hip, accessible and cheap, you’ll find a lot more of them showing up.