Which term refers specifically to a repeated bass line in music?

The term "basso ostinato" refers specifically to a repeated bass line in music. This technique is characterized by a short musical phrase that is persistently repeated in the bass while harmonies or melodies change above it. Basso ostinato can be found in various musical styles throughout history, from Baroque compositions to contemporary music. It serves as a foundation, allowing for variations and elaborate melodic development above it.

In contrast, an arpeggio involves the notes of a chord played in succession rather than simultaneously, which does not specifically pertain to a repeated bass line. The term "jazz ostinato" could imply a repeated phrase in a jazz context, but it doesn't exclusively refer to the bass line, thus making it less precise than "basso ostinato." An "active beat" generally refers to a rhythmic pattern that is engaging, but it does not specifically denote a repeated bass line and is more about the overall pulse and feel of the music.