As we mentioned when we launched the Arranging Ellington project, one of the musicians you have the option to include in your arrangement is the wonderfully talented and versatile singer Claudette Sierra. In addition to being an accomplished jazz vocalist, Claudette has performed with some of the titans of Latin music, including Tito Puente, Celia Cruz, and Ruben Blades.
If you are thinking of including Claudette's voice in your arrangement of "Come Sunday" or "Almighty God" — and I would definitely encourage everyone to seriously consider that possibility! — then you'll probably want to familiarize yourself with her voice and vocal style. The best way to do that would be to pick up a copy of her excellent album About Time and do some of that deep listening we've been talking about. You'll especialy want to zero in on how her voice sounds across every part of her range, from her lowest notes to her highest. The human voice changes timbre more radically than any instrument in different parts of its register, so you want to be attentive to that.
UPDATE: Claudette has generously offered to share with us a previously unreleased recording of her original song, "Sabanas." Here she is accompanied only by piano, and her beautiful, sensitive performance gives a vivid sense of what her voice is like across her range.
If you've never written for voice before, the most important thing to understand is that key selection for singers is incredibly important. If you don't have perfect pitch, you might not necessarily notice if an instrumental piece were to be transposed up or down by half-step, but for singers that half-step difference is very often night and day. It can easily be the difference between being able to sing the song and not being able to. Even when all the notes of a song fall within a singer's comfortable range, the distribution of those notes has a huge impact. A piece sung primarily in a vocalist's upper range has a very different emotional character than the same piece sung primarily in their lower range.
Key selection also has a huge effect on the intelligibility of sung text. Now, I should say that just because "Come Sunday" and "Almighty God" have lyrics doesn't mean you necessary have to use them — it's totally possible to write a wordless vocal part if you so choose, or to use the voice more like an instrument. [See Duke's "T.G.T.T" (AKA "Too Good To Title") from the Second Sacred Concert for a gorgeous example of the wordless approach.] But if you are going to include the lyrics, it's important to consider how vocal range influences our ability to understand the words. Of course, it all depends very much on the individual vocalist, but a general rule of thumb is that lyrics that are sung in the bottom and middle parts of a singer's range tend to be easier to understand than lyrics sung at or near the top of their range, which is why the highest notes are most often reserved for climactic emotional moments, lyrics we've heard earlier in the song, words that are very easy to understand, etc.
Given all of that, we'd like to offer a range of recommended keys for both "Come Sunday" and "Almighty God" that Claudette feels are best suited to her voice. That's not to say you couldn't select a different key for your arrangement, but that is a situation you'd want to handle with extreme care — and if you do that, you'll probably want to post a draft here and solicit Claudette's feedback.
[N.B. The original "Almighty God" modulates up a minor third at letter H — these key suggestions take that modulation into account, but your arrangement doesn't necessarily need to modulate.]
Singers: do you have any additional tips for those folks who are new to writing for voice? If so, I'd love to hear from you — please chime in in comments!