Original color 13.75 x 21.75 window card poster for Bill Monroe and His Blue Grass Boys, presented by WSM Grand Ole Opry at Atwood Stadium in Flint, Michigan on August 19, 1955. Printed in blue and red on white cardstock, the appealing poster features a portrait of Monroe at a WSM microphone. In very good condition, with intersecting folds (reinforced with tape to reverse), and light edge toning.