What is the Japanese song-metric filler?


In English we have some common sounds that are used to fill spaces in songs
like "ah" "la" "nah" "oh" "yea".

What do we use for Japanese songs?

So far I think I have only heard `る` used.




As for the short shouts, Japanese popular songs are influenced by American
culture, so you can hear almost anything that you would expect to be shouted
in an American or other English songs.

As for the sound used for some length, I think `ら` is the most popular one:

  * [桜らららら](http://www.youtube.com/watch?v=aafLEt9Mg9c#t=1m9s)
  * [悲しみにさようなら](http://www.youtube.com/watch?v=esKK8GO0Qas#t=3m48s)

A standard song sang in elementary school:

  * [気球に乗ってどこまでも](http://www.youtube.com/watch?v=PteQGzUAUt8#t=53s)

You can hear it throughout this song:

  * [人間なんて](http://www.youtube.com/watch?v=zaBXVZJSkns)

This one is made solely of this kind of sounds, and includes some variaties
(`あ`, `ん`, `ら`, `ふ`):

  * [北の国から](http://www.youtube.com/watch?v=4-3gnAk3G-w)

I found one with `や`:

  * [Yah Yah Yah](http://www.youtube.com/watch?v=AtLEgAUNfao#t=1m10s)

Conclusion is that `ら` is the most popular (and sometimes even `や`), and my
very rough guess is that this has connection to the fact that the epenthetic
consonant in Japanese is usually a liquid (r) or a glide (y, w) as you can
observe in the phonoloical rule applied to vowel ending verbs: `mi-u → miru
(見る)`, classically `mi-u → miyu (見ゆ)`, `mi-are-ta → mirareta (見られた)`




As for the short shouts, Japanese popular songs are influenced by American
culture, so you can hear almost anything that you would expect to be shouted
in an American or other English songs.

As for the sound used for some length, I think `ら` is the most popular one:

  * [桜らららら](http://www.youtube.com/watch?v=aafLEt9Mg9c#t=1m9s)
  * [悲しみにさようなら](http://www.youtube.com/watch?v=esKK8GO0Qas#t=3m48s)

A standard song sang in elementary school:

  * [気球に乗ってどこまでも](http://www.youtube.com/watch?v=PteQGzUAUt8#t=53s)

You can hear it throughout this song:

  * [人間なんて](http://www.youtube.com/watch?v=zaBXVZJSkns)

This one is made solely of this kind of sounds, and includes some variaties
(`あ`, `ん`, `ら`, `ふ`):

  * [北の国から](http://www.youtube.com/watch?v=4-3gnAk3G-w)

I found one with `や`:

  * [Yah Yah Yah](http://www.youtube.com/watch?v=AtLEgAUNfao#t=1m10s)

Conclusion is that `ら` is the most popular (and sometimes even `や`), and my
very rough guess is that this has connection to the fact that the epenthetic
consonant in Japanese is usually a liquid (r) or a glide (y, w) as you can
observe in the phonoloical rule applied to vowel ending verbs: `mi-u → miru
(見る)`, classically `mi-u → miyu (見ゆ)`, `mi-are-ta → mirareta (見られた)`

