<p>Have you won any national competitions for your compositions? What kind of recordings do you have? Who performed them? How many pieces have you written and for what variety of instrumentation? Your personal instrumental playing is of no consequence in a composition submission unless you’re auditioning into a formal music school or conservatory which requires composers to play an instrument - which is not what you’re talking about here - and, even there it would be secondary.</p>
<p>However, if you’ve won national level competitions on an instrument then submitting a performance supplement to Yale might be useful - but not unusual. From what I hear Yale is teeming with conservatory level musicians.</p>