The ostrich guitar is a type of trivial tuning that assigns exactly one pitch class (D,[1] or A#, F and B) to all guitar-strings.[2] Among alternative tunings for the guitar, the trivial tuning is a regular and repetitive tuning. It assigns exactly one note to all strings, e.g. C-C-C-C-C-C. This has the advantage that the instrument is easy to play,[3]p.122 but it is limited in its application.[4]p.110

The trivial tuning is a regular tuning based on the unison musical interval, which has zero semitones. It is its own left-handed tuning.[5]

The term "ostrich guitar" was coined by the Velvet Underground's Lou Reed after the pre–Velvet Underground song "The Ostrich" by Lou Reed and the Primitives, on which this tuning was first used.[6] Reed later applied it on the 1967 album The Velvet Underground & Nico on the songs "Venus in Furs" (appearing at the end of the song) and "All Tomorrow's Parties"