In Nomine

Title of a large number of English instrumental pieces (for viols, lute, or keyboard) based on a cantus firmus:  d f d d d c f g f g a.  This cantus firmus has nothing to do with the Introit "In nomine Jesu" but is quite similar to the melody of the Vespers antiphon of Trinity Sunday "Gloria tibi Trinitas."  The seemingly wrong designation is explained by the fact that the species originated with and developed from the "In nomine Domini" section from the Sanctus of Taverner's "Missa Gloria tibi Trinitas."  This section, like many others of this mass, employs the melody of "Gloria tibi Trinitas" as a cantus firmus.

The "In nomine" was the most favored type of cantus firmus composition in England after c. 1550.