Alan-a-Dale was the name of a character in Human mythology. Living in 12th century England, he was a member of the Merry Men, a band of outlaws led by Robin Hood who made their home in Sherwood Forest. He was a musician who played the mandolin.
In 2367 the entity known as Q transported the senior officers of the USS Enterprise-D into a recreation of Sherwood Forest and the story of Robin Hood in an attempt to teach Captain Picard a lesson about love. During the re-enactment each of the officers played the part of one of the Merry Men. The role of Alan-a-Dale was played by Lieutenant Commander Geordi La Forge. (TNG: "Qpid")