Named after a race of beings from Irish mythology, De Dannan are a folk group whose whimsical music unites the modern with the ancient. Though firmly rooted in traditional jigs and reels filled with spritely fiddles and bouncy accordions, their sound has also proven adaptable enough to incorporate elements of classical, klezmer and ragtime. Since the group came together in the mid-'70s, a long list of musicians have passed through De Dannan's ranks, including singers Dolores Keane and Maura O'Connell, each credited with some of the group's most arresting vocal numbers.