Celtic Harp Concert at NoBo In-Person Celtic singer/percussionist Beth Gadbaw and Celtic harpist/vocalist Margot Krimmel present Celtic music. They are known for their tight harmonies and thoughtful arrangements. This concert will also feature harp duets. The Boulder County Artists-in-Residence (2014) have recorded three studio albums together. https://calendar.boulderlibrary.org/event/13548952