A lot of thoughtful and even inspiring things have been said throughout this discussion.

Ana, the original poster, made quite a telling point a few hours earlier today, observing that singing is often taken less seriously than instrument-playing as a musical discipline, and even as a personal accomplishment. Sadly, this is sometimes true not only of insensitive observers, but even of those of us who ourselves sing and play. Playing quite obviously requires study and work and practice while singing, in comparison, "comes naturally" and depends, to an extent at least, upon having the "gift" of a reasonably listenable voice.

As singers, we really need to continually remind ourselves that working at the craft is essential and results in quality performance, and I think it's also important to maintain the sure knowledge and the attitude that the God-given or Nature-born "gift" of one's voice is not nearly so critical to our success as the determination to use that voice and the conscienciousness and taste we cultivate and bring to our efforts.

We all can think of famous and tremendously effective vocal performers, in most if not all of the different folk traditions we pursue, whose voices are by no means conventionally beautiful or pure, but who charm and engage us by their attention to the meanings and messages of their songs and by their ability to speak directly to our hearts. If this level of achievement is what we're striving for, the best "teachers" we're likely to find may not be available for regularly scheduled lessons. Indeed, some of them might not even be singers or musicians!

Marje brought up an interesting point about "ornamentation" versus plain, unadorned, earnest singing. It's absolutely true that "It's not about you, it's about the song [and that] the words matter, the tune matters." Our primary task is to understand the song and present it clearly with full consciousness of all its subtleties. However, certain of the traditions that many of us know and love do offer, and indeed to some extent require, the use of particular conventions of vocal "ornamentation." As Marje noted, this is certainly true of the Irish tradition(s), and I would add the additional observations that an entirely different, but essentially parallel, set of vocal embellishments is essential to the African-American vocal traditions upon which all Gospel, jazz, blues, and even pop music is based.

It's easy enough for a technically competant vocalist to employ a given set of these conventions, and to overdo it. It's another thing entirely to exhibit the taste and restraint required to put in just the right amount of trills and grace notes, and in just the right places, to enhance the meaning and feeling of a song without turning the performance into an exercise in egotism ~ "showing off." How does one learn where and how to draw the line? Not from x-number of once-a-week lessons, that's for sure; only from months and years of listening and learning, of performing and failing and gradually improving.