"Greensleeves" can have a ground either of the form called a romanesca; or its slight variant, the passamezzo antico; or the passamezzo antico in its verses and the romanesca in its reprise; or of the Andalusian progression in its verses and the romanesca or passamezzo antico in its reprise. The romanesca originated in Spain and is composed of a sequence of four chords with a simple, repeating bass, which provide the groundwork for variations and improvisation.