Plagal

[Sarah]

Having a scale running from the dominant to its octave; -- saidof certain old church modes or tunes, as opposed to those calledauthentic, which ran from the tonic to its octave. Plagal cadence, acadence in which the final chord on the tonic is preceded by thechord on the subdominant.

[Sarah]

To take someone by surprise; if something is a surprise to you. Also a musical cadence, in which the last chord is one which is not expected.