 One example of a re-entrant tuning for tenor guitar is D4–G3–B3–E4 with strings 3–1 as for the normal 6-string guitar, but string 4 tuned to D an octave above the 4th string of the 6 string guitar.The fifth string on the five string banjo, called the "thumb string", also called the "drone string", is five frets shorter than the other four and is normally tuned higher than any of the other four, giving a re-entrant tuning such as the bluegrass G4-D3-G3-B3-D4.The five string banjo is particularly used in bluegrass music and old-time music.