What phrase indicates a return to the original tempo in a musical piece?

The phrase that signifies a return to the original tempo in a musical piece is "A tempo." This instruction is commonly used in musical notation to direct performers to resume the speed of the music that was established at the beginning of the piece after a deviation, such as a ritardando or accelerando. It helps maintain the overall structure and expressive qualities of the music, ensuring that transitions between different tempos are clear and take the listener back to the intended pace of the composition.

In contrast, the other terms listed describe specific styles or speeds of music rather than instructing a return to the original tempo. "Andante" indicates a moderately slow tempo, often interpreted as moving at a walking pace. "Allegro" refers to a lively and fast tempo, suggesting an energetic and brisk performance. "Piano," while it indicates softness in dynamics, does not pertain to tempo but rather to the volume at which the music should be played. Understanding these distinctions between tempo markings and dynamic indications is crucial for interpreting musical scores correctly.