Although Guild’s thin-washed F-style flat-top shape was well-established by the early 1960s, the company could not ignore the enormous influence of traditional bluegrass and blues music, where the thick-waisted dreadnaughts of Martin and Gibson ruled.

In 1963, Guild joined the dreadnaught club with the mahogany Dreadnaught D-40 and the rosewood Dradnaught D-50 (Guild typically spelled dreadnaught with an a). To underscore the market at which these models were aimed, Guild quickly renamed them Bluegrass Jubilee D-40 and Bluegrass Special D-50, respectively.

Ironically, Guild was never able to crack the hold that Martin had on bluegrass players, but in folk music, Guild provided strong competition for the more established companies. Such popular performers as Tom Smothers and Richie Havens played Guilds, and one artist – Carolyn Hester – was better known for her Guild magazine ads than for her music. When Richie Havens appeared in the 1970 film “Woodstock”, vigorously strumming his D-40 as the festival’s opening act, Guild’s dreadnaught replaced the F-style as the company’s most identifiable acoustic model.