Johann Nepomuk Maelzel (1772-1838) and Beethoven's Battle Symphony
The inventor of the metronome, Johann Nepomuk Maelzel persuaded Beethoven to write Wellington's Victory (Battle Symphony), but their friendship wasn't to last.
Maelzel is known today as the inventor of the metronome. He was also the inventor of the Panharmonicon, a mechanical instrument that reproduced the sounds of the full orchestra.
In 1813 he met Beethoven in Vienna and persuaded him to compose a piece of music for his Panharmonicon to celebrate the victory of Wellington over the French at the Battle of Vitoria in Spain. Such was the success of the piece that Beethoven later orchestrated it and published it as Wellington's Victory (Battle Symphony) Opus 91. Maelzel made a series of ear trumpets to help Beethoven with his deafness.
For a short time they were spectacularly successful, but as his deafness worsened their amplification of sound became useless to him.
Beethoven fell out with Maelzel when Maelzel printed posters in late 1813 claiming the Battle Symphony was his own property - a gift from Beethoven. When Beethoven was told Maelzel was trying to get possession of the orchestrated score, he began legal proceedings against him, but it came to nothing when Maelzel left Vienna.
Maelzel died on a tour of America. The brig he was on, the Otis, went down on its way from Havana to Philadelphia. Maelzel - and his Panharmonicon - went down with it.