I read somewhere that your vocal 'type' (bass, baritone, tenor etc.) is determined more by the timbre of your voice than your actual range. For example, you could be a baritone but hit notes in the high tenor range. You'd still be a baritone because of the way your voice sounds.

Any truth in this?
Yes, and no. If I'm correct, voices are classified differently depending on the type of music (or something like that). Basically, what I mean to say is that in classical choral music, a voice would be classified based on its range, while in popular music (which in this case, includes metal, rock, everything), voice classification is based on timber. For example, I have a relatively low range, but my voice is very light and rather boyish. So, I sang bass when I was in choir, but I was considered a tenor/high baritone when I sang everything else.
Hmm. As almost everything else, it's a mixture of both.
If your tone is low, but you have the range of a tenor, you're definitely a tenor.
Sometimes the timbre can be used to determine the vocal type, if the vocal range isnt enough.
Remember, there are many different degrees of a vocal type. Just because you're a bass, doesn't mean you cant be very close to having the register of a baritone.
But to answer your question:
Yes. If the baritone has very good technique which enables him to blend his registers.
A lot of are mistaken being tenors, but the reality is that most people are baritones.
If you are a high baritone with incredible technique, chances are most people will call you a tenor.

In the end, it doesn't really matter at all.
The classification of your voice depends, regardless of genre, on your range.

Now, not all ranges are cut-and-dried. How about the classic example of the male who can sing an A above the baritone G but can't reach the tenor C? Technically, he is still a baritone, but for pop music and choral music purposes *may* be considered a tenor for all practical purposes - particularly if the upper part of his voice is stronger.

In any case, technically, he is NOT a tenor. It's just that he is higher than a baritone traditionally goes, and the demands of pop and choral music tend to be more conservative than the demands of traditional classical voice.

Could I get some more talent in the monitors, please?

I know it sounds crazy, but try to learn to inhale your voice. www.thebelcantotechnique.com

Chris is the king of relating music things to other objects in real life.