Final answer:
The song 'Smoke on the Water' by Deep Purple was inspired by a fire that occurred at a Frank Zappa concert at the Montreux Casino due to a flare gun incident.
Step-by-step explanation:
Deep Purple's iconic song Smoke on the Water was inspired by a real-life event that the band members witnessed. The inspiration came from a fire that broke out during a Frank Zappa concert at the Montreux Casino in Switzerland. In December 1971, as Zappa performed, someone in the audience fired a flare gun, setting the casino's ceiling ablaze. This incident led to the famous opening lyrics of the song: 'We all came out to Montreux on the Lake Geneva shoreline...'