melisma

noun

1. (countable)A passage of several notes sung to one syllable of text.

   “A choir sang one of the Lamentations of Jeremiah. The mournful melisma accompanied the slow procession to the palace built by Herod the Great, at present untenanted.”

   “At the top of the hill in the archway of the main house, an eyeless old man sat on a bucket, scratching at a two-stringed gourd, warbling weird melismas on a madman's text.”

2. (uncountable)The use of such passages.

   “A subsequent generation of singers, including Ms. Aguilera, Jennifer Hudson and Beyoncé, built their careers around melisma.”