M-20 Concert Acoustic Guitar Natural. Guild’s iconic M-20 was the first guitar off the production line in 1967, when the company had grown so much that they relocated to a new factory in Westerly, RI. Nearly 50 years later, history has repeated itself in a brand new, state-of-the-art facility in California. The M-20 is a concert size acoustic guitar built with solid mahogany top, back, and sides, informally nicknamed “the Nick Drake guitar” for its inclusion on the album art for Drake’s album, Bryter Layter. It features a rosewood bridge and fingerboard, bone nut and saddle, and an extremely light satin finish that allows this guitar to truly sing. The M-20’s modest appointments include a vintage style rosette and Guild’s peak logo inlaid in mother-of-pearl on the headstock. Each M-20 comes with a hand-signed, numbered certificate of authenticity, and ships with a hardshell case.