French horn
The French horn is a brass instrument that appears in Diary of a Wimpy Kid: Double Down. It is one of the instruments played in the Westmore Middle School band.
History
When Greg hears that Mariana Mendoza is only inviting members of the school band to her Halloween party, he visits an instrument store. Greg picks out the French horn, finding it cool-looking and thinking it is easy to play. Frank is surprised by the price and makes Greg promise to commit to playing the French horn, reminded of how he gave up playing the piano.
In the band, Greg notices how heavy his French horn and struggles to carry it. He also realizes that his French horn is a left-handed instrument while he is right-handed. He plays it, but instead makes a fart noise, and blames the supposed fart on Grayden Bundy. That night, he practices the French horn, but is unable to play it properly. He instead plays videos of a girl playing the French horn out loud to make Frank think he is practicing.
Later, Greg begins to lose interest in the school band. At the Fall Concert, he brings his French horn, but does not get to play in the concert due to getting locked in the band room with Rowley. Despite Frank still wanting him to practice the French horn, Greg gives up on it.