Final answer:
The lead instrument in Beijing opera is the jinghu, a two-stringed fiddle, which is distinctive from Cantonese opera where the lead instrument can change.
Step-by-step explanation:
In traditional Beijing opera, the lead instrument is consistently the jinghu. This contrasts with Cantonese opera, where the lead instrument can vary. The jinghu is a two-stringed fiddle that plays a central role in the musical accompaniment of Beijing opera, providing both melody and a harmonic foundation. In contrast, Cantonese opera might employ different leading instruments depending on the particular piece or style. The jinghu's distinctive timbre and the way it interplays with the vocal lines are characteristic of Beijing opera's unique sound. Understanding this aspect of Beijing opera provides insight into the broader cultural practices and artistic conventions that distinguish various forms of traditional Chinese theatre.