The shape and size of your body and your body coordination partly determine your tone. In addition, your tone changes with your moods or emotions. Check out the following list for factors that affect tone:
Body coordination: Coordinating the muscles in the body is important for creating lovely tone for singing. That coordination includes breath coordination, alignment, and articulation.
Emotions: Your emotions directly affect the tone of voice. You know when someone is happy or sad by the tone of voice. When you’re acting, you want to tap into your emotions so that the tone of your voice reflects the story you’re telling. Of course, it’s also possible to go overboard and let the emotions overtake you.
If you go too far emotionally, you end up crying and won’t be able to sing your song. Or maybe you’ll be so angry that you tense up and can’t sing well. Using your emotions is good, but allowing emotions to overtake you isn’t good.
Work on singing exercises to develop your technique. When your technical skill is solid, you’ll be able to maintain your technique even during the more emotional sections of your song.
Shape and size of your head and throat: If your mouth and throat are small, you have smaller vocal cords and probably a higher voice type. Singers with large mouths and heads tend to have bigger voices and can make bigger sounds.
Size of your body: Singers with a big, round chest tend to have a large lung capacity for nailing those high notes. You don’t need to have a big body to sing well, though — good singers come in all shapes and sizes.
Space: The amount of space you open for tone to resonate is a key element in the tone of your voice. If the space is tight, the tone is tight. If the space is open, the tone has room to resonate.
Tension: Even body parts far from your singing voice need to be free of tension to keep the tone of the voice free.