Music might make the world go round, but costumes and theatrics make it more fun.

Nobody knows this better than the Material Girl, who donned six widely different outfits, rode a mechanical bull and karate kicked a samurai warrior during the Saturday opener of her first tour in eight years, according to her spokesperson and Reuters.

Bringing a sold-out crowd of 18,000 to its feet, 42-year-old Madonna took the stage at the Palau Sant Jordi arena in Barcelona, Spain, to the tune of "Drowned World/Substitute for Love," dressed in a sleeveless black top, long leather pants and short kilt. (Click [article id="1444400"]HERE[/article] for photos of Madonna's Barcelona performance).

With 10 dancers and two backup singers accompanying her, the Queen of Pop delivered a two-hour, 22-song set heavy on material from her two most recent albums, 2000's Music and 1998's Ray of Light. She steered away from such career-defining singles as "Material Girl," "Like a Virgin," "Papa Don't Preach" and "Like a Prayer." Of her 12 #1 singles, she played only one, "Music."

The singer tossed in a few tunes (and looks) from throughout her 20-year career, though, including "Holiday" and "La Isla Bonita." During the latter she played acoustic guitar and wore an outfit similar to the one she sported in the song's 1986 video.

Madonna's well-rehearsed Drowned World Tour features the singer and her dancers flying around the stage on wires. The show also uses elaborate laser lights that at one point shot out from helmets worn by the dancers.

Her finale, according to Reuters, featured a video message from British comedian Ali G introducing the dance hit "Music" (Ali G played the limo driver in the song's video).

Madonna, who recently exhibited her developing guitar skills on "Late Show With David Letterman," picked up an electric ax for "Candy Perfume Girl," according to her spokesperson.

The celebrated performer's costumes, designed mostly by Jean-Paul Gaultier, included some of her past looks (see [article id="1444306"]"Madonna To Revisit Evita, Geisha Girl, Cowgirl Personas For Tour"[/article]).

Madonna played Barcelona again Sunday and is scheduled to hit Milan, Italy, Thursday and Friday. The European leg of her Drowned World Tour concludes in London on July 12. She begins a sold-out, three-month North American tour on July 21 in Philadelphia.

Set list for Madonna's tour opener, according to her spokesperson: