Last Saturday, an enigmatic combination of cultural and artistic diversity graced Slosberg Recital Hall. Barcelona-based Arabic/African folk-electronic fusion group Nettle entranced more than 100 listeners with music unlike anything heard before. It was the group's first official performance in the United States. Nettle: Music for a Nu World featured DJ/rupture, interviewed last week in JustArts, along with Moroccan violinist Abdelhak Rahal, singer and guembri player Khalid Bennaji, cellist Brent Arnold, percussionist Grey Filastine and visual artist Daniel Perlin. The concert, part of the MusicUnitesUS World Music series, was the final event of Nettle's three-day residency that included lectures and workshops prior to Saturday's performance.

The type of music Nettle plays is not easily described. As far as words go, they blend acoustic traditional Arab and African folk songs with electronic hip-hip/trance style drum loops. Rahal and Arnold play a lyrical, somber melody while Bennaji accompanies with traditional Moroccan guembri and Filastine fills in the space with sparse, thoughtful beats. DJ/rupture suddenly enters with a drastic and unnatural sound effect that perhaps causes listeners to wince. Eventually, the audience realizes the distortion and hard bass beats are no longer just an opposing force to the violin solo, but they are in some wild way, a complement.

And even if there is no moment of "Oh, this makes sense," Nettle keeps the listener wondering. Why is this dissonance so compelling? What is the effect of expressing two completely different sounds as one song?

Nettle began the concert with "El Lebrijano," a melancholy Arabian duet between Rahal and Arnold. Perlin, who projected images on a screen behind the musicians, complemented the tune with animated doves flying in sunlight. DJ/rupture made his entrance with an electric loop, which the instrumentalists embraced by entering into improvisation. Arnold's cello lines were distinct and matched the energy of the beats.

The concert continued with a variety of traditional Arab songs juxtaposed with Rupture's robotic sound effects and Perlin's trippy visuals. In one song, "Baladi Mehboub," Perlin presented a vague black and white picture. The screen consisted of a variety of blots and shapes that formed fleetingly larger pictures before disappearing. Meanwhile, a house/trance style beat merged the acoustic melodies and gave the visuals a subtle context.

In "Dead Western," images of several countries flashed on screen and quickly morphed into other countries. The combination of aural and visual dissonance showed that Nettle not only crossed boundaries of culture and identity but also of sensation. Everything that the audience heard or saw was a single experience.

Another piece with a distinct message was "Mahomi," a '70s Moroccan song sung by Bennaji and Rahal. "The song's message," explains Rupture, "is that although buildings will fall and wealth will fade, the one irreplaceable thing that we must cherish is children."

Nettle played an extra song, "Mama Mia Que Suerte," after the audience's applause signaled to Nettle that they wanted more. Another mix of the natural and unnatural-sounding, the song evoked both tribal and robotic imagery.

After the group left, the audience didn't simply leave the auditorium. Some stayed and discussed what they had experienced. One group argued over what the music represented, if anything. The performance, rather than relaxing listeners, provoked them to speak to the people next to them, trying to figure everything out.

In the end, there is no single definition that can be applied to the music that Nettle plays. As Arnold said at Friday's improvisation workshop, Nettle's goal was to "make something happen." The New York resident explains that improvisation arises not from specific melodies but from ideas. "When I improvise, I like to think, 'OK, it's my turn now, time to cause some trouble.' It could be anything, any goal, like making someone cry by just playing one note for the entire solo." Yet there is a moment, he describes, that the musician transcends objectives. "When the process becomes natural, you base your music more on emotions and shapes and images rather than notes." Arnold demonstrated this at the concert during the song "Tabla," where he screeched wildly with his mic'ed cello, utilizing the distortion to wail his emotions through the amplifiers.

This type of communication of emotions and ideas through music is central to Nettle. The musicians speak with each other in broken Spanish, a second or third language for most members. They usually only speak a few words, indicating which song to play. Yet once the music begins, a newfound synergy arises. Each member of Nettle connects seamlessly with the others through their most fluent common language of musical expression. What audiences saw last Saturday was merely a glimpse of a type of art that simultaneously provoked and connected with the audience.