Hometown post-punk heroes Sonic Youth played a free show for approximately 7,000 fans in Battery Park on July 4th as part of the River to River Festival. The decades-old band started the set with a spellbinding, spacey rendition of “She is Not Alone,” followed by the Kim Gordon-led classic “Bull in the Heather.” By the third song, a blistering “Silver Rocket,” 50-year-old frontman Thurston Moore seemed to have had enough of the photographers separating his band from the frenzied crowd, so he climbed down into the photo pit to thrash through the scrum, before getting back onstage to finish the song.

Other highlights from the 80 minute show: Kim Gordon forgetting the lyrics to “Drunken Butterfly” (teleprompter time?), prompting a big hug from Moore. (Later she said, “Not to make excuses but those lyrics don’t mean anything. Except the ‘I love you’ part.”) Moore sarcastically name-checking the NYC Waterfalls (“spectacular”) and, later, announcing that “Kim says I’m being annoying.” At which point he sank to his knees in front of Gordon for a dissonant slide-guitar solo, which culminated in a nasty “100%” to close the show. (Set list after the jump.)

And after a nearly 17 year absence from performing, The Feelies opened for Sonic Youth with a tight, upbeat set of new wave songs made incandescent by the propulsive guitar work of Glenn Mercer and Bill Million. There’s a great article in the Times about how the band resurfaced for the gig at Thurston Moore’s request: “I had this fond memory of the Feelies always playing on American holidays,” Mr. Moore said. “I thought, ‘Why don’t we get the Feelies? Do they exist?’ ”