Who: Anyone can learn to sing. For some, it comes easier than others, but it is a learnable skill. You just have to be willing to try, and not beat yourself up when things aren’t perfect, and practice to the best of your ability.
Age: I take students of all ages–my oldest students have been in their seventies!–however, I only accept students younger than 12 on a case-by-case basis after an initial interview and trial lesson and require that they take a joint piano+voice lesson, for reasons related to vocal health and development. I strongly encourage parents of singing-loving children to have their child take piano lessons anyway in order to develop the skills singers need to enjoy lifelong music-making. (And my piano students all get a little singing experience as part of their piano lessons, which I customize to the student who wants to also sing.)
The main thing to understand about voice lessons:
Singers in particular have to deal with the two separate parts of making music: technique and style.
My teaching is based on finding out what your individual voice can do–all of it, singing, laughing, talking, shouting, acting–and building up your skills in using that unique voice in a healthy, free, joyful, expressive way. That is healthy technique.
At the same time, we look at what you want to do with your voice and how you take your healthiest (and developing) technique and apply it to the style of singing you want to do. I have taught and continue to teach students whose styles are everything from opera to jazz to rock to gospel to traditional church music and everything in between.
We set goals and pick repertoire (songs and exercises) that build your technique and make progress toward you singing in the style you want to sing. And we do it with great good humor, patience, laughter, focused work, and no self-trash-talk. Each day we sing at today’s personal best.