Trombone/Legato Tongue

A legato tongue is a very light tongue when playing trombone. It requires notes to be sustained their full duration, while having quick slide motion. Think of making a small indent in the wall of air passing into the trombone. You don't want to stop air flow or distrupt it but mearly show that it's not a slur being played. Playing staccato is kind of the opposite of legato tongue.