A turn is like a trill that goes both up and down.
Typically, its a 5 note deal
You start on theoriginal n ote, go up one scale step, back down to theoriginal note, donw one scale step, and then end up on the original note again.
if melody is A:
A B A G A
The turn can eitehr stat on the same beat as the original note or precede that note as a type of grace note phrase.
Tags: embellish melody, trill