I'm glad you've explained the word. I had come across it but not taken the trouble to find out what it was. I didn't even know there was a word for this, but now I can explain what it is that irritates me about modern wannabe pop singers.

I know there are legitimate uses for melisma - in musical works where each note is notated and sung deliberately, or in gospel where it has its place in intensifying the emotion of the song in worship; but the way it's used now, to mangle and distort up both the words and the tunes of what were once perfectly good songs with endless, self-indulgent ad-libbing, that's something different.

I'm very pleased that I now have a word for it.

Marje