An annual institution of experimental sounds in Barcelona, Sonar jumped the Atlantic this year and touched down in two of Chicago’s most elaborate settings this weekend for what organizers hope will be the first of an annual stateside showcase of the avant garde in the shaping of sound.

The free three-day event included several lectures and a selection of movies but performance was the focus and the festival was handed the keys to Chicago’s Millennium Park and the Frank Gehry-designed Pritzker Pavilion for the opening night concert on Thursday evening. Cloudy skies and the early arrival of fall temperatures might have tamped down the crowd numbers a bit, but did nothing to impact the performers on stage.

Plenty of lawn space and no shortage of seats in front of the stage were available as …