Why are some songs often played on the radio, the vocal pitch increase trick for almost each note

 

At your risk.

i have the impression that a good singer may be doing it consciously. Now that i know it i can hear it if i concentrate on the part of each note after the attack which for some reason may be wrong (flat ie below correct pitch) even for the best singers. Is it how our mind works?

What ever the reason if we concentrate on correcting the poor note the feedback mechanism we create gets it right by subtle glissando. Cybernetics in singing. 

For example the first "me" at 0:20, in phonetics notation, mi: or mii the second i is clearly higher so that the singer and listener's mind is happy.

Examples are everywhere on radio but these 2 were heard today on Rock FM in Athens, Hellas.

Another example, i can not remember on which FM radio station it was heard a few days ago:

i heard about this trick from a serious looking intelligent person while i was doing my military service, long time ago. i could not really believe what he was saying. It took me many years to digest and rediscover.

It surely helps me enjoying singing.

Of course there are many more elements that can make a song liked, please see for example Hit Song Ingredients - euroelectron.