Though I'm known mainly for teaching the bluegrass instruments, I do often have advice for my students with regards to their voices. I leave the technical aspects of singing to trained voice teachers and concentrate with my students on the stylistic elements of bluegrass vocals. I think most students can improve their singing with some thought and attention to details. I ask my students to listen very carefully to recordings of their favorite bluegrass singers and emulate the singing - an approach much like they would use for their instrument. Occasionally I will help students with harmony singing, showing them baritone or tenor parts and helping them understand how these parts are constructed. I have written out some harmony parts on some common vocals songs.
In my Really Good Book of Bluegrass Lyrics I wrote the following about what I consider to be the important points of developing a good bluegrass voice.
The Elements of Bluegrass Singing
Understanding the elements of singing is important in developing one's voice. While it's true that many talented singers have given little thought to the elements listed below, most singers would do well to pay some attention to them. As is the case in learning an instrument, you can greatly improve your voice through study and practice: many of the great bluegrass singers continue to improve throughout most of their careers.
Melody: This simply refers to the notes of a song as they might be written down. Singing the melody is the most obvious component of a song performance, but its importance should not be overlooked. When learning a new song, make sure to pay close attention to the melody as sung by your source. If you're learning a song by Lester Flatt, start by singing the melody as Lester does. Later, when you know it correctly, you can use your own variations.
Phrasing: How the words are timed to fit into the lines of the song is known as phrasing. Bluegrass has its own distinctive phrasing, often with syncopated words sung just ahead of the beat. It is common to hear less experienced singers phrase improperly. Many times this is because they have relied too much on reading the lyrics without listening to their source of the song. It is also common for beginners to phrase too much on the beat, especially when they are new to singing while playing their instrument. Make sure to listen closely to the phrasing when learning a new song.
Pitch: This is the accuracy with which one sings the intended notes. In the end, this has probably been the downfall of more bluegrass singers than any other element. Singing requires an accurate sense of pitch. Some singers have this from the day one, while others have to work on it. Often the problem has much to do with failure to listen to one's own voice. Good singers are always listening to themselves and fine-tuning their pitch as they sing. Want to take a pitch test? A couple of minutes here at the Adaptive Pitch Test will tell you how discerning your ear is.
Tonal quality: Singing isn't just about technical elements. Also important is the tonal quality of one's voice. There is no way to define good tone, because it varies so much, but the great singers have some quality about their voices, beyond pitch, phrasing, and melody, that makes their voices compelling. For the most part, tone is a result of a person's natural voice resonance, but a surprising amount can be developed. Many great singers have found a way to favorably shape their tone, consciously or otherwise. If you feel you are not satisfied with your natural tonality, work on improving it. In a sense, it's not unlike the process that voice impressionists must go through. And remember, bluegrass has many great singers, with a huge variety in tone.
Projection: This is the volume of your singing. It's important to be able to project your voice above the din of all the instruments and also match your volume to your singing partners'. While much of this is certainly innate ability, proper singing and breathing technique can improve projection, as can practice. Realize too, that those with quieter voices can be on a more equal footing when microphones are being used.
Enunciation: This is the clear pronunciation of your words as you sing. Usually voice teachers deal with improving a student's diction, and this is important, but in bluegrass there is the additional concern of over-enunciating. You should make your words understandable — don't slur or mumble, but also realize that bluegrass came from rural-based musicians, and word pronunciation often reflects this; words like going , for instance, are usually pronounced goin' .
Style: There are many elements that don't fit into the above categories and can be classified as stylistic elements. The great singers are known for these. Lester Flatt and Jimmy Martin would sometimes break their voices at the end of lines; Bill Monroe and Joe Val often would sing notes or entire lines in falsetto; Ralph Stanley and Hazel Dickens are masters of quick vocal turns; Monroe and Flatt would often slowly slide into sustained notes from below. All of these are stylistic elements that add much to a vocal performance. Make sure to think about how and when to use them. Also important is knowing what not to do. Vibrato, for example, is used minimally in bluegrass.