|Old Hat Makes You All That|
|Jack of All Trades|
In terms of high school playing, French Horn players are the most suitable players to be good at a variety of instruments. The embouchure is fairly compatible with Bb and F Altos. Also making it worth your while, Bb instruments can be played as F instruments using proper trigger fingerings.
General Instrument Tips
In general, you should treat all instruments as if they have every feature possible. Hold and play them as if they have all features. Never rest any instrument on your lap to play.
Holding the French Horn
To create the appropriate French Horn position, start by standing up. Stick your hand into the bell and manipulate your hand until you find the widest position that you can create a stopped tone. Then open the bell and hold it up with your thumb and forefinger knuckles. Your left hand should have a rather firm grip on the valves. Hold the horn at an angle such that your body doesn't block the bell. If your band director disagrees with you holding the horn this way, too bad. Tell him someone on the internet said this is how its done.
Playing Alto Horns
Alto Horns play like any other brass instrument (ie not like the French Horn) and use the same fingerings as the Trumpet and so forth. Always hold Alto Horns up off of your lap using your left arm for most of the support. Marching Alto Horns can be tucked into your right elbow for additional support. On a Marching Alto Horn, your left hand goes in the gap between the third valve slide and the body unless there's no room. On an upright, hold the horn up by the third valve slide as if it had a fourth valve.
Be sure to use an appropriate mouthpiece. Alto Horn requires a rather large deep cupped mouthpiece. It is not a Marching Mellophone, and as such, it does not play well with small mouthpieces.
Playing Mellophone and Mellophonium
The awkward shape of the Mellophone is intentional. The bell is intended to be aimed at the floor to mask some of its harshness. Hold the Mellophone with your right hand on the valves like a Cornet and use your left hand to hold the horn up with your thumb in the gap between the third and first valve slide. Only tilt the horn if it's built to be held at an angle.
Mellophone is a Cornet derivative and as such, it plays best with a large Flugelhorn mouthpiece. A small Alto Horn mouthpiece may also be sufficient. I've never tried it, but a Bach 12C Mellophone mouthpiece might actually work well. The classic big Mellophone mouthpieces are not actually the best. They generate a large amount of overtones (likely to mask the bad intonation) and play very stiffly.
Playing Marching Mellophone and Marching French Horn
These instruments are all intended to be like a Trumpet. Your right thumb goes on top of the lead pipe. Your left hand holds the valve cluster. Be sure to hold the horn up slightly above vertical to avoid looking sloppy -- especially when marching!
Marching Mellophone is a Trombone derivative and thus plays very well with an Alto Horn mouthpiece. If at all possible, use this style mouthpiece when playing Marching Melly. The people around you will thank you.
Playing Bb Instruments (Trumpet/Flugelhorn)
The most important thing that a French Horn player needs to know about Bb instruments is that they can be used to play French Horn parts!
Refer to my previous Complete Fingering Chart. A low C on F music is equivalent to low G on a Flugelhorn. There is a caveat that you are limited to a lowest note of low B natural unless you have a fourth valve. Be sure to practice using instruments in this fashion. You never know when it might come in handy. You can do the same on F instruments to play music in C in case that isn't incentive enough.
Holding normal piston valve Bb instruments is obvious enough, so let's talk about rotary Bbs. Hold the horn with the your left index finger on the provided finger rest near the third rotor and bell. Your left thumb goes on the first valve slide (or third valve trigger if provided). Use your remaining knuckles to hold the weight of the horn at the third rotor. Now put your right thumb on the provided bracket between the horn body and first valve slide. Hold the horn at an angle (right hand lower) to give you a comfortable hand position and view. Don't hold the horn with your hand on the bell. It looks dumb.