Why do I keep cracking notes?

[tubaguy9]

A LOT of it has to do with hearing the pitch...brass is a very vocal-like instrument, and in order to play a note right, you need to hear it in your head...

[Tuba Guy]

Ask your teacher
and use more air

[windshieldbug]

I know this is not what you want to hear, but...

play by sound, not by feel.

[pierso20]

Ask your teacher
and use more air

Good idea, I will ask my teacher as soon as possible. From what I've noticed, the notes particularly tend to crack when I am playing very loud, or piano. To get a good "piano" marking sound, are we supposed to use less air? I've heard that we should use slower air, but I don't see how that's possible. Slower air = lower note right?

I was actually working with a student on this today.

you use 'slower' air when quieter but don't confuse 'slower' with 'unsupported'. Your diaphragm should still be working as much on soft playing as in louder playing. Instead of thinking 'slower' air, I tend to think of "wider" air. This especially helps in low register playing.

More "relaxed" "lips" = lower note.

If they crack at a loud dynamic, then you may be forcing the dynamic with your embouchure rather than your air support and air stream. Try working dynamics with your air and not with your embouchure.

And of course, ask the teacher since your teacher can actually see it in action.

[Alex C]

Too much muscle tension.

[tubashaman2]

.

[timayer]

It might be as simple as the slides on the valves aren't set right. If you're trying to play a note right on pitch, but the horn is set to play it 5 cents lower, it'll give you a bit of a fight, and that might result in note cracking. I do agree that the first thing to work on is air flow and knowing where the sound is, but beyond that, sometimes resetting slides helps. Just make sure that if you do that, you're setting them to play in tune rather than where you want to play the notes. Then you might need to reteach your lips where the notes are.

[eupher61]

better still, just to add on to the buzzing suggestion/recommendation (I second it totally!) record your buzzing practice, and watch in a mirror. Are your chops moving a lot with the articulation?
Listen to your buzzing, after every few notes played. Analyze them for accuracy, are there any scoops, drops, fraks, goobles of any kind?

If you have a recorder that will play back at half speed, or even quarter speed, that will be of great help in this analysis.

Talk with your teacher. Maybe that mouthpiece isn't really right for the horns you're playing now. You've changed, but the mouthpiece hasn't...