a decorative musical accompaniment (often improvised) added above a basic melody
source: WordNet 3.0
Originally, a double song; a melody or counterpoint sung above the plain song of the tenor; a variation of an air; a variation by ornament of the main subject or plain song.
source: Webster 1913
verb
sing in descant
source: WordNet 3.0
sing by changing register; sing by yodeling
The Austrians were yodeling in the mountains.
source: WordNet 3.0
talk at great length about something of one's interest
