It often happens that a man (maybe baritone) starts singing eg Happy birthday and the rest just start singing along. How is it that tenors are able to sing along when the baritone chooses a low key? I as a tenor dont like singing with baritones since they choose too low keys. Nobody ever told me singing along with baritones could be that hard.
The range of Happy Birthday is only one octave - in F, it goes from C to next C. That's not a particularly great range, given that most people have a good two octaves of range themselves. So, pretty well wherever it starts - in whatever key, most people will be able to reach all of the notes. probably one of the reasons it has stood the test of time! And, of course, there's always the option of singing it an octave higher, or an octave lower.
Happy birthday is one of the most used songs and it is the most violated tunes - even more than we are the champions!
If a Bariton begins low and the Tenor is able to sing the first notes he will be able ti sing the whole song as there is no lower tone as the head motive.
But when the Baritone sings too low the Tenor may let drop the two first up-beats happy birthday and enter with a forte to you! and after the third up-beat comes the great hour for the Tenor as all others sing wrong and he is the only one who gets the correct pitch!
'Tenor' is a quality of voice, not a range limit. And just because a soprano or tenor CAN get a top C, it doesn't mean she can't contribute perfectly well to 'Happy Birthday' in an alto range.
If you want effective community singing, keep to a range from just under Middle C to just over the next C up. You, as a tenor, might not be hitting your 'money notes' But is it really THAT hard for you to use that register?