When I play mallets I sometimes have trouble hitting the right notes. Is there anything I can do to help with my coordination when playing mallets?

There's one simple thing you can do, it's called practice.

Take it slow and only increase tempo AFTER you've mastered the part at a slower tempo.

Word. Slow practice is the key to getting good at just about anything you want to play.

Things to remember when you practice. Make sure that every rep you take has perfect technique. With an inconsistent technique you are training the wrong muscles. By using the correct technique every time you approach the board you are creating a lasting muscle memory that will kick in when you speed up tempos. Make sure that your hands are relative to your body. So your body orientation is not reaching 2 feet to your left (or right), and make sure you are moving your body with the notes. Body orientation is very important for note accuracy as it can directly affect the hand position for the stroke. Yes yes before people jump on me there ALWAYS exceptions to everything (especially for mallet work).

Overall you just need time on the board... Getting your hands familiar with the keys. I'm not sure what technique your using or even if it's concert or drum corps approach. But either one you pick has the consistency of technique that produces a quality and consistent sound with every stroke that you take. Consistent is the key word especially when you move your hands on a board to accurately hit a bar that is around 3 inches thick (compared to a snare drum).

Hope this helps!

If you want better coordination on the keyboard the best route to follow is scales. That's how I did it, and plus now I know all my scales. Start every scale real slow, use a metronome at it's lowest setting and go up 1 interval (on the metronome) each time. I learned all my Major scales in around 2 weeks. After those two weeks every aspect of my playing, mainly note accuracy, was ten times better.

one click at a time? That is a little unnecessary. You need to bump up tempo's anywhere from 6-10 clicks so that your muscles can feel the difference in the stroke as it gets faster. Learning how the control at various tempos and what your hands need to do as things get faster... Because this is not a perfect world and your hands don't exactly play the same at 60 and at 200.

On the metronome bumping topic, go somewhere in the middle. It depends what tempo you're at, because the difference between 30 and 35 BPM is much larger than the difference between 180 and 185 BPM in actual feel. If you're under about 70 beats per minute, adding 2 or 3 BPM each time is usually appropriate. It's enough that you can feel a difference, but not so much that the tempo increase isn't overwhelming. Between about 70 and 130, adding 4 BPM is usually a good number. And above 130, adding 5 BPM is usually good. Obviously, this is because adding, say, 5 BPM at 180 makes a much smaller difference than adding 5 BPM at 30.

It's important not to bump the tempo too fast, because if you bump the tempo too fast, you'll most likely worry more about the speed of your hands than the accuracy of notes, and it's a waste of time to practice wrong notes. On the other hand, if you increase too slowly, practicing becomes cumbersome and boring. Just figure out what works for you.

See, view it the other way... As note accuracy is very important. During practice I think that developing a good stroke with good technique at any tempo is the key. Anyone can get down notes... But the players I look for can play with a good full sound and correct approach at 30 or 200. Technique can't be fully learned in a morning block. Notes can.

I guess that is the drum corps way.

Scales. Practice doing leaps with one hand to the other. Make up excercises that will serve the purpose for helping you become more accurate. START SLOW and then increase the tempo.

I agree with Apollo, Scales are the way to go. Start with C major and then go to C sharp, then D and so on. It helped me anyway. Just work with the tempo your confortable with. Most song are based off of scales anyway so this may help with your accuracy.