Husband-and-wife duo Aaron and Nicole Keim will perform folk ballads, gospel harmonies and Americana on a range of modern and vintage instruments, including ukuleles built by lutier Aaron Keim of May-Moe Ukuleles near Hood River, at 8 p.m. Wednesday, May 15, at Headwaters Environmental Center, 84 Fourth St. The cost is $10 at the door. A ukulele workshop will held at 5:30 p.m., and costs $25. Call 541-488-9474 or 541-482-4489 for information.