Here’s a solid list from art critic Jerry Saltz about “how to be an artist”, much of which is applicable to musicians as well. (I don’t know how artists relate to Saltz—I suspect with the same circumspect suspicion with which musicians regard our critics. But that’s fine—we’re not their audience.)
I liked the following chunk particularly; just replace “statement” with “program note”.
Don’t use art jargon; write in your own voice, write how you talk. Don’t try to write smart. Keep your statement direct, clear, to the point. Don’t oppose big concepts like “nature” and “culture.” Don’t use words like interrogate, reconceptualize, deconstruct, symbolize, transcendental, mystical, commodity culture, liminal space, or haptic. Don’t quote Foucault, Deleuze, Derrida. Those guys are great. But don’t quote them. Come up with your own theory. People who claim to hate or have no theory: That’s your theory, you idiots!
Important things are hard to write about. That’s the way it is. Deal with it. And if it’s pretentious to say, don’t say it.
I find that most program note writing suffers less from overuse of technical “art jargon” than simply from a reliance on bromide and cliché; Jeremy Denk goes into this in his indispensible manifesto from a few years ago.