Intonation or pitch is the holy grail of singers. Without it, you could have the most beautiful vocal tone in the world, but you will have trouble singing for a whole gig…
We all want to avoid singing sharp or flat, yet this is easier said than done. Which other instruments can you think of where the pitch is not divided up by keys or frets? Not many… I guess the other instruments may be trombone (they slide through the notes) and fretless bass.
When your abdomen is tense, this may be the cause of you being sharp. When you are flat check if your tongue is tense by gently padding the underside of the chin with the thumbs. Of course if you really want help with your voice there may be other causes such as the position of your larynx, thyroid tilt etc. But I don’t want to get too deep into this (especially in a blog such as this!)
If you have the gift of perfect pitch, you are both lucky & cursed at the same time! Lucky because you can adjust super accurately until you are perfectly in tune & cursed because anyone else in the band being out of tune will be torture for you 🙂
Relative pitch is something every singer can aspire to AND achieve.
Make it your goal to develop your own internal sense of pitch either by feel or by ear.
Some vocalists sing with good steady pitch even when they cannot hear themselves onstage because they can remember how it feels to sing the notes.
If you do it by sound alone, this may be more challenging for you at gigs when your voice is not reaching notes or singing above the pitch it should be.