Ground bass
English variation form over a constantly repeated bass.
What it means
The ground is an English variation form over a constantly repeated bass. The bass, itself called the “ground,” stays the same or almost the same in every repetition while melodies and accompaniment figures unfold ever anew above it.
Musical use
The ground was especially popular in England in the 16th and 17th centuries, for instance in virginal music and in songs and instrumental pieces. Henry Purcell wrote several works over a ground, among them the aria “When I am laid in earth” from the opera Dido and Aeneas, in which a descending, constantly recurring bass carries Dido's lament.
The ground should be distinguished from the passacaglia and the chaconne, continental forms that likewise vary over a repeated bass but are usually in triple metre and use other typical bass models. The ground is the English form of the basso ostinato.
Performance practice
When playing a ground, attend to the clear, even repetition of the bass as a foundation, and shape the upper parts so that every repetition seems new and heightened. Plan dynamics and ornaments over the whole chain of variations.