Write a concise feature that uses Mellencamp’s Rock Hall moment as a lens to explore the pressures and unpredictability of live performance. Begin with a vivid scene of the moment, then explain how key changes, pitch, and on-stage dynamics can derail a performance even for seasoned artists. Integrate a brief, accessible explainer on music acoustics and monitoring that would help readers understand what went wrong. Include quotes or paraphrase from Mellencamp’s account to ground the piece in human emotion and humility. Close with a forward-looking note on what modern tech and rehearsal practices have changed in live shows.