Alverno Presents director David Ravel says he knew last year's Global Union music festival was a success when he saw two African-American women dancing to a Serbian punk metal band.

If there's a musical thread beyond the big tent classification of world music, it's that it crosses cultural and artistic boundaries.

This year's lineup offers further proof: Haale is a New York singer who grew up listening to her Persian parents' native music and Jimi Hendrix. Roberto Rodriguez and Maurice El Médioni are an alliance of Algerian and Cuban musicians.

This weekend, Global Union will return with two days of free music at the Humboldt Park band shell near E. Oklahoma and S. Howell avenues. The music will run from noon to 7 p.m. Saturday and Sunday.

Milwaukee has lots of music festivals, most of them designed to entertain and lubricate beer sales. There's obviously an educational component in Alverno's festival that's bolstered by the accessibility of a free event. But Ravel doesn't want things to sound too academic.

"First and foremost, it's great music," he says. "It's fun. We want to have a good time with the music of cultures outside our own."

Global Union originally came about because of a chance meeting backstage that led to an invitation to coordinate events with the World Music Festival in Chicago and the University of Wisconsin-Madison World Music Festival.

It was an opportunity that Ravel jumped at. Having three regional festivals running concurrently meant that routing would be financially feasible, and a focus on world music is part of the stated mission of Alverno Presents.

Ravel says last year's event drew a diverse crowd of 6,000. Food vendors at this year's event include Outpost Foods, Debby Jo's Ribs, World on a Plate, West Bank Café and All Fruit Smoothies.

Here's a look at this year's Global Union lineup.

Dobet Gnahore: From the Ivory Coast, Gnahore uses female backup singers and an acoustic guitarist that gives her music a softer, warmer tone than most Afro-Pop music. She's a student of African singing styles and works in more than a half-dozen African languages. If you like Miriam Makeba or even India.Arie, you might enjoy Gnahore as well.

By: Dave Tianen