Okay, so tensionometers run around $60. I'd get one if I planned to build a lot of wheels, but I'm not. From my understanding, experienced mechanics can judge proper tension by plucking the spoke, like a guitar-string, and hearing the note. Now, I'm a musical person, and have close-to-perfect pitch, would love it if any of you could tell me about what the note (or range of notes) associated with an ideally tensioned spoke. If type of spoke matters, I use 14/15/14 for most of my wheelbuilding. The one especially in question is rear wheel, drive-side.
Also, note that you don't need perfect pitch to do this - just compare to a guitar or piano.
Do people use this sort of technique? It makes sense, but I've never heard anyone refer to the actual note.