As we said on Metronome, we actually need to time our singing, so that it is all even, as incredible as it may seem. It does make a sensible difference.
We have recorded Let's Do This Thing of I Love You (Let's) without a timer and we have recorded I Laugh (Lyrics) with a timer: Oh, what a difference! See yourself: Maquiavelica
The thing is realistically timing it all, just like we see Bobby Vee doing here: Bobby Vee
We had noticed that there is a substantial difference between his video and the video of Leo Sayer, who changed the song quite a lot in terms of presentation. Bobby Vee seems to pronounce all the words correctly and with a lot of effort to produce the correct articulation with his mouth. He seems to keep the same time length for each line he sings. Leo Sayer does not seem to do the same (Leo) in what regards the time length at least.
We think that that DOES MAKE a substantial difference in the quality of the sound we receive, since the music becomes more pleasant, remarkable, and easier to sing/accompany. You will probably notice that you will keep the lines of Bobby in your mind more easily than you will keep the lines of Leo. The human mind seems to work better with even production of sounds, therefore. That does match our impression in what regards the English language: That it is more pleasant to everybody because it is more even in terms of ups and downs, like it actually has a very short interval of variation. Latin American languages, such as Portuguese, seem to tire us up in terms of both listening and speaking because they, first of all, vary too much in terms of ups and downs, like in the same sentence or in general.
A good instrument to use these days to time your singing, since we do not yet have a voice metronome, despite our suggestion (see Metronome), is this stopwatch: Stopwatch. This is completely free of charge and anyone can use at home, in their garage.