We are about to do our percussion fitting sessions (I like the word fitting better than tryout because there isn't anything they can do to prepare).
This year we are doing them before placing woodwinds and brass and doing it in small groups instead of individually to see how they handle group instruction and to assess things like self control and following directions- they almost always have self control when parents are with them and done individually- we want to see how they function in a new environment with a small group of peers and a teacher. We decided to score/observe them in the following areas (in no particular order):
1) following directions 2) self-control 3) coordination 4) body awareness 5) timing 6) natural stroke/grip (ability to do a good stroke with relaxed joints and control- gets a natural grip without much extra instruction needed- can look and match easily without having to need multiple corrections)
We will also be assessing their desire to do more than just drum, prior knowledge (piano experience is helpful), and paying close attention to how they transition from task to task and stay focused on the task at hand.
My biggest desire from a musical standpoint is natural timing and coordination. My biggest desire from a personality standpoint is self control and ability to follow directions.
I think the percussionists need to be more self directed and self controlled than other students in the band to be successful. Our percussionists that have not done well and not stuck with band struggled with self control and staying on beat- they have to be able to handle the "stress/pressure" of the band depending on them to keep good time or it negatively affects the entire band. You need to select students that can handle the spotlight and will embrace the challenge and responsibility.
Last thing- the ability to shake off mistakes and not get bogged down with needing to always be perfect is a trait that seems to be common amongst successful drummers in all styles of music. Detail oriented enough to get things right, but not allowing yourself to get paralyzed when you mess up- keeping the beat above all else is what is needed by percussionists. We will also be observing this as we give them some tasks that are really too hard for them to handle just to see how they handle not being able to do something perfect the first time.
There's a LOT to learn in percussion and rhythmic notation can get in the way of them reading mallet instruments fluently if they don't work on it consistently - which many won't, because "they play the drums." Already having the basics of that skill helps a ton.
2. Do they have rhythmic awareness?
If they can't keep a beat, they don't need to be a percussionist. While this skill CAN and SHOULD be learnable BY ANYONE, as a twelve year old, it should already be intrinsic to the kid. If they don't have a solid internal sense of rhythm, place them elsewhere.
3. Are they a behavior problem?
Percussionists sit in the back of the classroom furthest away from the teacher (when on the podium), play the "easiest" music (when it comes to most concert literature) and have the most "toys" available to them in class. Do they have the self discipline to not be an issue, or will they turn it into playtime? Check their behavior records from their feeder elementary. If they're consistently getting into trouble, percussion is likely not a good fit for them.
For me, those are my three biggest "must haves" as a percussionist. I'd prefer them to have piano skills since they directly translate to mallets but that's not something that's as common as it was a generation ago.
A less important "4. Can their parents/guardians afford to purchase them the appropriate equipment?" is also something to be considered. Percussion is *expensive* - both up front and ongoing with buying replacement sticks and mallets. You can't *really* make that a requirement, but it's something to consider.