Slingerland #11 Birds Eye Maple Tenor Banjobeautiful 1920s 30s Slingerland number 11 Tenor Banjo. 17 fret, 21 scale length. Birdseye maple pot, maple neck, friction tuners. Plays and sounds fantastic. The Slingerland Number 11 tenor banjo, dating from the 1920s and 1930s, is a classic instrument produced by the Chicago based Slingerland company, which was better known for its drums but manufactured a wide range of banjos under the May Bell brand and the Slingerland name.