I'm a woman who has generally fit more into the alto range, and I haven't sung formally for more than five years. For the past few years, I've noticed that I've generally found it more comfortable to sing along along the higher portions of the tenor range.
I can "make" myself sing at a slightly higher range -- for instance, I don't have too much trouble singing to the alto version of "Gute Nacht", which should be a major sixth higher. (It's in my range, but this isn't the section of it that I would instinctively sing at.) However, the timbre of my voice feels different.
My voice feels a lot more "airy", when I intentionally sing at the higher section, so long as it isn't too high for me. Conversely (although perhaps this is because I'm an alto), my voice feels a lot "fuller" in the lower section. Moreover, when I "naturally" ascend to the higher portion, this difference seems slightly reduced.
Is this just some normal, perhaps idiosyncratic variation in timbre, or have I hit on something more generalized (e.g. head voice v.s. chest voice)?
I suspect that I've hit on that problem and probably need to do a bit of experimenting, but my school choir instructors conflated "chest voice" with "bad singing" and "head voice" with "good singing", and not with anything related to range or timbre. I'm now stuck wondering if I've been relying too much on my "chest voice", as someone interested in classical works. (Aside: is this issue with chest voice even something I need to worry about, or have my teachers taught me wrong?)