<p>First, how old is your son, and does he intend to pursue music as a career path, just play recreationally, or at this point is there no way of knowing?</p>
<p>The answers and advice (at least from what I'll offer) will vary.</p>
<p>If he is at all serious about music, and in high school or just entering, and potentially thinking of taking a music path, I'd suggest the more competitive program and the alternate teacher. I would strongly urge a trial lesson with the prospective teacher to see if student and teacher can work together, as this is a primary factor in successful student/mentor relationships; you see that now with his current teacher. (See added thought)</p>
<p>Multiple teachers on the same instrument is usually a no-no at the intermediate and beginner stages, and can be a sore point even at the advanced and pre-professional level. A lot will depend on the teacher's willingness to accept another source of input, particularly if the teachers have no knowledge of the other's rep or style. Sometimes, just ego gets in the way. On the other hand, there are noted teacher pairs (particularly in strings), where the student is effectively obligated to work with both.</p>
<p>The reality is that in a high level experience, the student actually has a number of teacher/mentors and can gain valuable musical knowledge (not necessarily instrumental expertise) from any number of sources... orchestral/ensemble directors, section coaches, chamber coaches, stand partners, peers.</p>
<p>I can't speak to percussionists in general, but if there are different areas of expertise on the different instruments, a potential working relationship between two teachers might be arranged. It has to be done openly, and with the full cooperation of all parties involved.</p>
<p>If he's still in middle school, and not sure how far he wants to go with music, I'd let him stay where he is. He's happy, learning, and having fun, with a teacher he enjoys. If he decides to step up the pace, you still have time to move forward next year.</p>
<p>One thought... a higher level program now will probably sort out for him if he's ready, willing and dedicated enough to WANT to pursue music as a career. The intense levels often discourage all but the most passionate. If it's in their blood, they tend to "know" early. If he's marginally interested, finding out now is better than as a freshman BM candidate.</p>
<p>Added thought: son, a violist, had a chamber coach who was for all intents and purposes his primary mentor. Juilliard trained, student of Delay, NY Phil chair. He would often seek her advice or interpretation of specific technicalities. She was the one who recommended his viola teacher. She would tell him in heavily accented Russian "Yes, Pavel TOLD you to play it like that. But if you want it to sound the way it was written, you VILL play it like this, (and then would demonstrate). You must play like violist, but THINK like violinist!"</p>