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Best instrument ever. It is perfectly balanced between the upper ranges and lower ranges. The best of both worlds. Woman mellophone lines in the last ten years in drum corps rings have notorious scored higher than those made only of men. Mellophone, in the key of F, may sound flat, but it is actually the tone quality (ok, the instrument itself is impossible to play not flat, everyone else tune down). Mellophone's always play the meanest licks and the greatest dynamics.
TOB Judge: Sopranos suck. Their high notes are so horrific. Wow, that mellophone double E was beautiful. God I love the mellophone.
by Candie4 August 03, 2006
A fairly large frontal facing insturment which some people call a marching French Horn.

I like to define it as follows.

Mellophone, Noun - A trumpet(not capitalized) with a bigger penis. Used by those who either play Horn in symphony or have realized in all of their infinite wisdom that trumpets suck at life.
"Mellown" player: "I'm a Mellophone player, I'm out of tune always but I make up for it by playing at retarded volumes because dynamics don't matter in marching band, right?

Mark: "I'm a trumpet player and that makes me a horrible person, I'm stupid, annoying, and ugly, no one will ever love me genuinley, and pain and misery will haunt my pathetic life for all eternity"
the single most amazing instrument in a marching band, ever. it is usually played by those of higher intelligence and awesomeness, aka concert F Horn players. ALWAYS louder than the trumpets. no exceptions.
trumpet player: dude i have to march in front of you guys during the show. i cant even hear myself think!
mellophone player: good. that means we are doing our job!
by -kriel- December 21, 2008
The greatest of the forgotten instruments in band. Mellophones are the marching version of a French horn, because french horns don't project properly to be used for marching. Many schools nowadays don't have them however, since EWHS is the best, we do. They're played in corps and often the people that play them are pretty timid, unlike their similar looking trumpets. Mellophones are the best!!!
Mellophone Player: I play the mellophone
Non Bandgeek: What's that?
Mellophone player: It's a trumpet looking object in the key of F which a huge bell the size of a French horn bell.
by Melodie October 22, 2004
A mellophone is what french horn players march and play in marching band. It's like a trumpet with a horn bell. Trumpet players call it a trumpet on steroids. But really, a trumpet is an anorexic mellophone.
Trumpet Player 1: Man! What is that thing?!
Trumpet Player 2: It's a mellophone. AKA a trumpet on steroids.
Trumpet Player 1: Ohhh! That's funny!
Mello Player: Really??? 'Cause I heard you play an anorexic Mello??
by Marching_Horn_Mello_Rocks April 11, 2010
the most awesome instrument in marching band. in concert band, the mellophone players are french horn players, which epically pwn anyway, so when they change to mellophone, its just as awesome. people may make fun of them, but its just cause they're jealous.
trumpet player says: haha, stupid mellophones

trumpet player thinks: ahh, i wish i could be a mellophone. they look so cool.
by bandgeek3453 November 28, 2009
An instrument commonly used for marching bands and drum corps. Basically a trumpet that has suffered both repeated instances of anal rape and consensual anal sex, resulting in a key of F, standing for Fucked in the ass. Often referred to comically as the prison trumpet by those who play trumpet, an instrument that has been spared vicious anal sex.
I'm a mellophone player, therefore I play an instrument that has been raped by me and dozens of other men at the same time resulting in an enlarged bell.
by Teehee1324 December 25, 2011