For Steve Halleck, a New Canaan resident who moved to town three years ago, the music of the 1960’s holds a certain nostalgia, and it keeps him going out to see that cherished music live. So on a recent early evening, Halleck made his way to Waveny for the first midweek installment of the hugely popular Summer Concert Series that resumes on Wednesday with country western group Gunsmoke (a concert sponsored by the New Canaan Community Foundation). “I’m here for the music,” Halleck said as foldout chair- and cooler-toting locals found their own spot of bright green lawn out back of Waveny House on June 21. “I’m here for the memories, to hear the music I grew up with,” he said. The night marked Halleck’s first time at the concert series, and as an avid fan of ‘60s R&B, he couldn’t miss it.