Johann Sebastian Flathead (728–789) was the son of King Mumberthrax and one of the Twelve Flatheads. He composed since his early years and when he was only 11 years old, his work became the first symphony played by the Frobozz Philharmonic Orchestra.
He wrote hundreds of symphonies, each longer than the previous (inversely proportional to the attendance of his diminishing audiences). Boswell Barwell postulates that the general public had so short an attention span that they couldn't sit still for the whole time of a single symphony. His Symphony #981 aka Infinite Symphony contained over 60000 movements. It was performed only once, while members of the orchestra retired and were replaced by their children or grandchildren.
In 771 GUE he was appointed official court composer by his brother, Dimwit Flathead. Soon later he wrote Flatheadia Overture for Rack and Pendulum to celebrate Dimwit's new dungeon.
He composed music for grandiose instruments, such as the Concerto for Woodwinds and Waterfalls. In 789 GUE he was in a rehearsal for his Minuet for Violin and Volcano when he was killed, an effect of the Curse of Megaboz.
- Johann is named after German classical music composer Johan Sebastian Bach.