pronunciation - Repeating the vowel sound of the mora that precedes gemination in songs

I noticed that in songs, the vowel sounds of the morae that come before geminations are sometimes repeated.

For example, the first lyric line of “マジカルちょーだいっ” is sung as しらんぷりをしたあって where the line is actually しらんぷりをしたって.

Another example: in the second lyric line of “片道きゃっちぼーる”, the final あった sounds like ああった.

Also, at the beginning of the song “Gem Stone”, the repeated もってる is pronounced as もおってる.

My questions are:

1. 
   

   Is this way of pronouncing gemination limited to songs, or are there instances where it's used elsewhere?

   
   


2. 
   

   It seems to be limited to songs with children or children-like voices, so is it by chance the way Japanese children initially pronounce gemination?

   
   

Answer

It is common in songs, and it is not specific to children’s songs.

In the first case, the pitch of the lyric line is probably something like:

し(G) ら(G) ん(G) ぷ(G) り(G) を(F#) し(G) た(E) っ(F#) て(D)

but if you try to sing this as it is, there is a problem: gemination is not a sound but just a pause, and you cannot sing it with any pitch. Therefore, the vowel preceding the gemination is prolonged to fill the first part of the mora which should filled by the gemination:

し(G) ら(G) ん(G) ぷ(G) り(G) を(F#) し(G) た(E) ーっ(F#) て(D)

I did not check the other two videos, but I guess that they arose for the same reason.